Alfa Laval Pump Handbook - Second Edition 2023

Pump
Handbook
All you need to know...

Second edition 2023
The information provided in this handbook is
given in good faith, but Alfa Laval is not able
to accept any responsibility for the accuracy
of its content, or any consequences that may
arise from the use of the information supplied
or materials described.

if Pumps
are the
question…
Alfa Laval is an acknowledged market
leader in pumping technology, supplying
centrifugal and positive displacements
pumps worldwide to the dairy, food,
beverage and pharmaceutical industries.

2 Alfa Laval Pump Handbook
2.0 Terminology and Theory
Explains the terminology and theory of pumping
applications.
2.0 Terminology & Theory 12
2.1 Product/Fluid Data 14
2.1.1 Rheology 14
2.1.2 Viscosity 14
2.1.3 Density 18
2.1.4 Specific Weight 19
2.1.5 Specific Gravity 19
2.1.6 Temperature 20
2.1.7 Flow Characteristics 20
2.1.8 Vapour Pressure 25
2.1.9 Fluids Containing Solids 25
2.2 Performance Data 26
2.2.1 Capacity (Flow Rate) 26
2.2.2 Pressure 26
2.2.3 Cavitation 37
2.2.4 Net Positive Suction Head (NPSH) 38
2.2.5 Pressure ‘Shocks’ (Water Hammer) 43
3.0 Pump Selection
Gives an overview of the pump technologies available
from Alfa Laval.
3.0 Pump Selection 46
3.1 General Application Guide 48
3.2 Pumps for Sanitary Applications 52
3.3 ALiCE Configuration Tool 54
4.0 Pump Description
Gives a description of Alfa Laval pump ranges.
4.0 Pump Description 56
4.1 Centrifugal Pumps 56
4.1.1 General 56
4.1.2 Principle of Operation 58
4.1.3 Design 58
4.1.4 Pump Range 62
4.2 Rotary Lobe Pumps 71
4.2.1 General 71
4.2.3 Pump Range 72
4.3 Circumferential Piston Pumps 76
4.3.1 General 76
4.4 Twin Screw Pumps 79
4.4.1 General 79
Contents
1.0 Introduction
Gives a short introduction to the Pump Handbook.
1.0 Introduction 6
1.1 What is a Pump? 8

3
Contents
Alfa Laval Pump Handbook
7.0 Pump Sizing
Describes how to size an Alfa Laval pump from
product/fluid and performance data given.
7.0 Pump Sizing 116
7.1 General Information Required 118
7.2 Power 119
7.2.1 Hydraulic Power 119
7.2.2 Required Power 120
7.2.3 Torque 121
7.2.4 Efficiency 122
7.3.1 Flow Curve 125
7.3.2 Flow Control 130
7.3.3 Alternative Pump Installations
Pumps Coupled in Series 133
7.4 Worked Examples – Centrifugal
Pump Sizing (Metric units) 136
7.4.1 Example 1 136
7.4.2 Example 2 142
7.4.3 Example 3 146
7.5 Worked Examples – Centrifugal
Pump Sizing (US units) 149
7.5.1 Example 1 149
7.5.2 Example 2 154
7.5.3 Example 3 158
7.6 Positive displacement Pumps 161
7.6.1 Slip 161
7.6.2 Initial Suction Line Sizing 164
7.6.3 Performance Curve 164
7.6.4 Pumps fitted with Bi-lobe Rotors
(Stainless Steel) 180
(Non Galling Alloy) 180
7.6.6 Pumps with Electropolished
Surface Finish 181
7.6.7 Guidelines for Solids Handling 182
7.6.8 Guidelines for Pumping Shear
Sensitive Media 185
7.7 Worked Examples – Positive
Displacement Pump Sizing (Metric units) 186
7.8 Worked Examples – Positive
Displacement Pump Sizing (US units) 206
5.0 Pump Materials of Construction
Describes the materials, used in the construction of
the Alfa Laval pump portfolio.
5.0 Pump Materials of Construction 82
5.1 Main Components 82
5.2 Stainless Steel 88
5.3 Stainless Steel Surfaces 90
5.4 Elastomers 92
6.0 Pump Sealing
Describes the principle of pump sealing and illustrates
the different sealing arrangements used on Alfa Laval
pump ranges.
6.0 Pump Sealing 94
6.1 Mechanical Seals 98
6.2 Mechanical Seal Types 109

4
Contents
9.0 Motors
Describes electric motors, including information on
motor, methods of starting, motors for hazardous
environments and speed control.
9.0 Motors 254
9.1 Output Power 258
9.2 Rated Speed 259
9.3 Voltage 261
9.4 Cooling 262
9.5 Insulation and Thermal Rating 263
9.6 Protection 264
9.6.1 Basic UL/CSA/Nema Enclosure Types 264
9.7 Methods of Starting 266
9.8 Motors for Hazardous Environments 268
9.9 Energy Efficient Motors 271
9.9.1 Minimum Energy Efficiency Regulations
(MEPs) 271
9.10 Speed Control 273
9.11 Motor Sizing Values 275
9.11.1 Torque 275
9.11.2 Speed/Frequency 276
9.11.3 Torque/Frequency 276
10 Cleaning Guidelines
Provides cleaning guidelines for use in processes
utilising CIP systems.
10 Cleaning Guidelines 282
10.1 CIP (Clean-In-Place) 282
11 Compliance
Describes some of the international standards and
guidelines applicable to Alfa Laval pump ranges.
11 Compliance 288
11.1 Compliance with International
Standards and Guidelines 288
8.0 Pump Specification Options
Gives descriptions of the various specification options
available for the Alfa Laval pump ranges.
8.0 Pump Specification Options 226
8.1.1 Port Connections 228
8.1.2 Heated/Cooled Pump Casing 230
8.1.3 Drainable Pump Casing 230
8.1.4 Clear Impeller Flow 231
8.1.5 Inducer 231
8.1.6 Motor 231
8.1.7 Legs 232
8.1.8 Other Centrifugal Pump
Specification Options 232
8.2 Positive Displacement Pumps 233
8.2.1 Rotor Form 233
8.2.1.1 Circumferential Piston Pumps 234
8.2.1.2 Rotary Lobe Pumps 234
8.2.1.3 Twin Screw Pumps 237
8.2.2 Clearances 238
8.2.3 Port Connections 240
8.2.4 Rectangular Inlet 243
8.2.5 Heated/Cooled Pump Casing 245
8.2.5.1 Circumferential Piston Pumps 246
8.2.5.2 Rotary Lobe Pumps 246
8.2.5.3 Twin Screw Pumps 247
8.2.6 Pump Overload Protection 247
8.2.7 Surface hardening 250
8.2.7.1 Rotary lobe pumps 250
8.2.7.2 Twin Screw pumps 250
8.2.8 Ancillaries 250
8.3 Q-doc 252
8.4 Alfa Laval Condition Monitor 253

5
Contents
5
15 Glossary of Terms
Explains the various terms found in this handbook.
15 Glossary of Terms 370
12 Installation Guide
Covers guidelines relating to pump installation, system
design and pipework layout.
12 Installation Guide 300
12.1 General 300
12.1.1 System Design 302
12.1.2 Pipework 303
12.1.3 Weight 303
12.1.4 Electrical Supply 303
12.2 Flow Direction 304
12.2.1 Centrifugal Pumps 304
12.2.2 Rotary Lobe & Circumferential
Piston Pumps 305
12.2.3 Twin Screw Pumps 306
12.3 Baseplate Foundations 307
12.4 Coupling Alignment 309
12.5 Considerations for
LKH Prime Centrifugal Pump 310
12.6 Pre-start Checklist 312
12.6.1 Fastenings 312
13 Troubleshooting
Offers possible causes and solutions to most common
problems.
13 Troubleshooting 314
13.1 General 314
13.2 Common Problems 317
13.2.1 Loss of Flow 317
13.2.2 Loss of Suction 317
13.2.3 Low Discharge Pressure 318
13.2.4 Excessive Noise or Vibration 318
13.2.5 Excessive Power 318
13.2.6 Rapid Pump Wear 318
13.2.7 Seal Leakage 319
13.3 Problem Solving Table 320
14 Technical Data
Includes a summary of nomenclature and formulas
used in this handbook.
14 Technical Data 324
14.1 Nomenclature 326
14.2 Formulas 327
14.3 Conversion tables 333
14.3.1 Length 333
14.3.2 Volume 333
14.3.3 Volumetric Capacity 333
14.3.4 Mass Capacity 334
14.3.5 Pressure/Head 334
14.3.6 Force 334
14.3.7 Torque 334
14.3.8 Power 335
14.3.9 Density 335
14.3.10 Viscosity Conversion Table 336
14.3.11 Temperature Conversion Table 338
14.4 Water Vapour Pressure Table 340
14.5 Pressure Drop Curve for
100 m ISO/DIN Tube 341
14.6 Velocity 342
14.7 Equivalent Tube Length Table 343
14.7.1 ISO Tube Metric for Water at 2 m/s 343
14.7.2 ISO Tube Feet for Water at 6 ft/s 349
14.7.3 DIN Tube Metric for Water at 2 m/s 355
14.8 Moody Diagram 362
14.9 Initial Suction Line Sizing 363
14.10 Elastomer Compatibility Guide 364

This chapter gives a short introduction
of the Pump Handbook.
6
1.0
Introduction

Introduction
1
.0
7
1.0
Introduction

1.1 What is a Pump?
There are many different definitions of this but at Alfa
Laval we believe this is best described as:
‘A machine used for the purpose of trans-
ferring quantities of fluids and/or gases,
from one place to another’
This is illustrated above transferring fluid from tank A to
spray nozzles B.
Pump types generally fall into two main categories
- Rotodynamic and Positive Displacement, of which
there are many forms as shown in Fig. 1.1b on the
following pages.
The Rotodynamic pump transfers rotating mechanical
energy into kinetic energy in the form of fluid velocity
and pressure. The Centrifugal and Liquid Ring pumps
are types of rotodynamic pumps, which utilise centrifu-
gal force to transfer the fluid being pumped.
The Rotary Lobe pump is a type of positive displace-
ment pump, which directly displaces the pumped fluid
from pump inlet to outlet in discrete volumes.
B
A
Pump
Fig. 1.1a Typical pump installation
8
1.0
Introduction

9
1.0
Introduction

Pumps
Positive
Displacement
Rotor
Multi-Rotor
Screw
Circumferential
Piston
Gear
Internal External
Rotary Lobe
Alfa Laval
Rotary Lobe
Single Rotor
Reciprocating
Diaphragm Plunger
Simplex
Multiplex
Piston
Archimedean
Screw
Flexible
Member
Peristaltic
Vane
Progressing
Cavity
Pump Classifications
Fig. 1.1b Pump classifications
10
1.0
Introduction

Rotodynamic
Multi-Stage Single Stage
End Suction Double Entry
Process
Rubber Lined
Submersible
General
Alfa Laval
Centrifugal and
Liquid Ring
11
1.0
Introduction

This chapter explains the terminology and
theory of pumping applications, including
explanations of rheology, flow characteristics,
pressure and NPSH.
In order to select a pump two types of data are
required:
• Product/Fluid data which includes viscosity,
density/specific gravity, temperature, flow
characteristics, vapour pressure and solids
content
• Performance data which includes capacity
or flow rate, and inlet/discharge pressure/head
Different fluids have varying characteristics and are
usually pumped under different conditions. It is
therefore very important to know all relevant product
and performance data before selecting a pump.
12
2.0
Terminology
and
Theory

Terminology and
Theory
2.0
13
2.0
Terminology
and
Theory

2.1 Product/Fluid Data
2.1.1 Rheology
The science of fluid flow is termed ‘Rheology’ and
one of its most important aspects is viscosity which is
defined below.
2.1.2 Viscosity
The viscosity of a fluid can be regarded as a measure
of how resistive the fluid is to flow. It is comparable
to the friction of solid bodies and causes a retarding
force. This retarding force transforms the kinetic
energy of the fluid into thermal energy.
The ease with which a fluid pours is an indication of its
viscosity. For example, cold oil has a high viscosity and
pours very slowly, whereas water has a relatively low
viscosity and pours quite readily. High viscosity fluids
require greater shearing forces than low viscosity fluids
at a given shear rate. It follows therefore that viscosity
affects the magnitude of energy loss in a flowing fluid.
Two basic viscosity parameters are commonly used,
absolute (or dynamic) viscosity and kinematic viscosity.
Absolute (or Dynamic) Viscosity
This is a measure of how resistive the flow of a fluid is
between two layers of fluid in motion. A value can be
obtained directly from a rotational viscometer which
measures the force needed to rotate a spindle in the
fluid. The SI unit of absolute viscosity is mPas in the
so-called MKS (metre, kilogram, second) system, while
in the CGS (centimetres, grams, seconds) system this
is expressed as 1 centipoise (cP) where 1 mPas = 1
cP. Water at 1 atmosphere and 20° C (68° F) has the
value of 1 mPas or 1 cP. Absolute viscosity is usually
designated by the symbol µ.
Kinematic Viscosity
This is a measure of how resistive the flow of a fluid is
under the influence of gravity. Kinematic viscometers
usually use the force of gravity to cause the fluid to
flow through a calibrated orifice, while timing its flow.
The SI unit of kinematic viscosity is (mm2
/s) in the so-
called MKS (metre, kilogram, second) system, while in
the CGS (centimetres, grams, seconds) system this is
expressed as 1 centistoke (cSt), where 1 mm2
/s = 1
cSt. Water at 1 atmosphere and 20° C (68° F) has the
value of 1 mm2
/s = 1 cSt. Kinematic viscosity is usually
designated by the symbol ν.
Relationship between Absolute and Kinematic
Viscosity
Absolute and Kinematic viscosity are related by:
ν = µ
ρ
Where ρ is the fluid density (see section 2.1.3)
In the CGS system this translates to:
Kinematic Viscosity (cSt) = Absolute Viscosity (cP)
Specific Gravity
or
Absolute Viscosity (cP) =
Kinematic Viscosity (cSt) x SG
A viscosity conversion table is included in section
14.3.10.
14
2.0
Terminology
and
Theory

Viscosity Variation with Temperature
Temperature can have a significant effect on viscosity
and a viscosity figure given for pump selection pur-
poses without fluid temperature is often meaningless
- viscosity should always be quoted at the pumping
temperature (Fig 2.1.2a). Generally, viscosity falls with
increasing temperature and more significantly, it in-
creases with falling temperature. In a pumping system
it can be advantageous to increase the temperature of
a highly viscous fluid to ease flow.
Newtonian Fluids
In some fluids the viscosity is constant regardless of
the shear forces applied to the layers of fluid. These
fluids are named Newtonian fluids. At a constant tem-
perature, the viscosity is constant with change in shear
rate or agitation (Fig. 2.1.2b).
Typical fluids are:
• Water
• Beer
• Hydrocarbons
• Milk
• Mineral Oils
• Resins
• Syrups
Viscosity
Temperature
Viscosity
Shear Rate
Fig. 2.1.2a Viscosity variation with
temperature
Fig. 2.1.2b Newtonian fluids
15
2.0
Terminology
and
Theory

Non-Newtonian Fluids
Most empirical and test data for pumps and piping
systems has been developed using Newtonian fluids
across a wide range of viscosities. However, there are
many fluids which do not follow this linear law, these
fluids are named Non-Newtonian fluids (Fig. 2.1.2c).
When working with Non-Newtonian fluids, we use
Effective Viscosity to represent the viscous character-
istics of the fluid as though it was Newtonian at that
given set of conditions (shear rate, temperature). This
effective viscosity is then used in calculations, charts,
graphs, and ‘handbook’ information.
Types of Non-Newtonian Fluids
There are a number of different types of Non-
Newtonian fluids, each with different characteristics.
Effective viscosity at set conditions will be different,
depending on the fluid being pumped (Fig. 2.1.2d). This
can be better understood by looking at the behaviour
of viscous fluids with changes in shear rate as follows:
Pseudoplastic Fluids
Viscosity decreases as shear rate increases, but initial
viscosity may be so high as to prevent start of flow in a
normal pumping system (Fig. 2.1.2e).
Typical fluids are:
• Blood
• Emulsions
• Gums
• Lotions
• Soap
• Toothpaste
• Yeast
It is not always obvious which type of
viscous behaviour a fluid will exhibit, and
consideration must be given to the shear
rate that will exist in the pump under
pumping conditions. It is not unusual
to find the effective viscosity as little as
1% of the value measured by standard
instruments.
Viscosity
Shear Rate
?
?
?
Viscosity
Shear Rate
Viscosity
Shear Rate
Normal
Viscometer
Reading
Typical Shear
Rate in Pumping
System
Fig. 2.1.2c Viscosity against Shear Rate
Fig. 2.1.2e Pseudoplastic fluids
Fig. 2.1.2d Viscosity against Shear Rate
16
2.0
Terminology
and
Theory

Dilatant Fluids
Viscosity increases as shear rate increases (Fig. 2.1.2f).
Typical fluids are:
• Clay Slurries
• Paper Coatings
Thixotropic Fluids
Viscosity decreases with time under shear conditions.
After shear ceases, the viscosity will return to its origi-
nal value - the time for recovery will vary with different
fluids (Fig. 2.1.2g).
Typical fluids are:
• Cosmetic Creams
• Dairy Creams
• Greases
• Stabilised Yoghurt
Anti-thixotropic Fluids
Viscosity increases with time under shear conditions.
After shear ceases, the viscosity will return to its origi-
nal value - the time for recovery will vary with different
fluids (Fig. 2.1.2h). As the name suggests anti-thixo-
tropic fluids have opposite rheological characteristics
to thixotropic fluids.
Typical fluid is:
• Vanadium Pentoxide Solution
Rheomalactic Fluids
Viscosity decreases with time under shear conditions
but does not recover (Fig. 2.1.2i). Fluid structure is
irreversibly destroyed.
Typical fluids are:
• Natural Rubber Latex
• Natural Yoghurt
Viscosity
Shear Rate
Fig. 2.1.2f Dilatant fluids
Viscosity
Time
Fig. 2.1.2g Thixotropic fluids
Viscosity
Time
Fig. 2.1.2h Anti-thixotropic fluids
Viscosity
Time
Fig. 2.1.2i Rheomalactic fluids
17
2.0
Terminology
and
Theory

Plastic Fluids
Need a certain applied force (or yield stress) to over-
come ‘solid-like structure’, before flowing like a fluid
(Fig. 2.1.2j).
Typical fluids are:
• Barium X-ray Meal
• Chocolate
• Tomato Ketchup
2.1.3 Density
The density of a fluid is its mass per unit of volume,
usually expressed as kilograms per cubic metre
(kg/m3
) or pounds per cubic foot (lb/ft3
) (Fig. 2.1.3a).
Density is usually designated by the symbol ρ.
1 m3
of ethyl alcohol has a mass of 789 kg
i.e., density = 789 kg/m3
1 ft3
of ethyl alcohol has a mass of 49.2 lb
i.e., density = 49.2 lb/ft3
It should be noted that some fluids would
have both thixotropic and pseudoplastic
behaviour.
Density in gases varies considerably
with pressure and temperature but
can be regarded as constant in fluids.
Stress
Shear Rate
Y = Yield Stress
Y
1 m
Mass of
ethyl alcohol
789 kg
1
m
1
m
1 ft
Mass of
ethyl alcohol
49.2 lb
1
ft
1
ft
Fig. 2.1.2j Plastic fluids
Fig. 2.1.3a Density
18
2.0
Terminology
and
Theory

2.1.4 Specific Weight
The specific weight of a fluid is its weight per unit
volume and is usually designated by the symbol γ.
It is related to density as follows:
γ = ρ x g
Where g is gravity
The units of weight per unit volume are N/m3
or lbf/ft3
Standard gravity is as follows:
g = 9.807 m/s2
g = 32.174 ft/s2
The specific weight of water at 20° C (68° F) and
1 atmosphere is as follows:
γ = 9790 N/m3
= 62.4 lbf/ft3
Note:
Mass should not be confused with weight. Weight is
the force produced from gravity acting on the mass.
2.1.5 Specific Gravity
The specific gravity of a fluid is the ratio of its density to
the density of water. As this is a ratio, it does not have
any units of measure (Fig. 2.1.5a).
1 m3
of ethyl alcohol has a mass of 789 kg
- its density is 789 kg/m³
1 m³ of water has a mass of 1000 kg
- its density is 1000 kg/m³
Specific Gravity of ethyl alcohol is:
789 kg/m³ = 0.789
1000 kg/m³
or
1 ft3
of ethyl alcohol has a mass of 49.2 lb
- its density is 49.2 lb/ft3
1 ft3
of water has a mass of 62.4 lb
- its density is 62.4 lb/ft3
Specific Gravity of ethyl alcohol is:
49.2 lb/ft3
= 0.789
62.4 lb/ft3
This resultant figure is dimensionless, so the Specific
Gravity (or SG) is 0.789.
1 m
Mass of
ethyl alcohol
789 kg
1
m
1
m
1 m
Mass of
water
1000 kg
1
m
1
m
Fig. 2.1.5a Specific gravity
19
2.0
Terminology
and
Theory

2.1.7 Flow Characteristics
When considering a fluid flowing in a pipework system
it is important to be able to determine the type of flow.
The connection between the velocity and the capac-
ity of a fluid (similar to water) in different tube sizes is
shown in table 14.6.
Under some conditions the fluid will appear to flow
as layers in a smooth and regular manner. This can
be illustrated by opening a water tap slowly until the
flow is smooth and steady. This type of flow is called
laminar flow. If the water tap is opened wider, allowing
the velocity of flow to increase, a point will be reached
whereby the stream of water is no longer smooth and
regular but appears to be moving in a chaotic manner.
This type of flow is called turbulent flow. The type of
flow is indicated by the Reynolds number.
Temperature is a measure of the internal
energy level in a fluid, usually expressed
in units of degrees Centigrade (°C) or
degrees Fahrenheit (°F).
2.1.6 Temperature
The temperature of the fluid at the pump inlet is usually
of most concern as vapour pressure can have a signi-
ficant effect on pump performance (see section 2.1.8).
Other fluid properties such as viscosity and density
can also be affected by temperature changes. Thus, a
cooling of the product in the discharge line could have
a significant effect on the pumping of a fluid.
The temperature of a fluid can also have a significant
effect on the selection of any elastomeric materials
used.
A temperature conversion table is given in section
14.3.11.
20
2.0
Terminology
and
Theory

Velocity
Velocity is the distance a fluid moves per unit of time
and is given by equation as follows:
In dimensionally consistent SI units
Velocity V = Q
A
Where:
V = Fluid Velocity (m/s)
Q = Capacity (m3
/s)
A = Tube Cross Sectional Area (m2
)
Other convenient forms of this equation are:
Velocity V = Q x 353.6
D2
Where:
Q = Capacity (m3
/h)
D = Tube Diameter (mm)
or
D2
Where:
V = Fluid Velocity (ft/s)
Q = Capacity (US gal/min)
D = Tube Diameter (in)
or
D2
Where:
Q = Capacity (UK gal/min)
Fluid velocity can be of great importance especially
when pumping slurries and fluids containing solids.
In these instances, a certain velocity may be required
to prevent solids from settling in the pipework, which
could result in blockages and changes in system
pressure as the actual internal diameter of the pipe is
effectively decreased, which could impact on pump
performance.
21
2.0
Terminology
and
Theory

Turbulent Flow
This is sometimes known as unsteady flow with
considerable mixing taking place across the pipe
cross section. The velocity profile is more flattened
than in laminar flow but remains fairly constant across
the section as shown in Fig. 2.1.7b. Turbulent flow
generally appears at relatively high velocities and/or
relatively low viscosities.
Transitional Flow
Between laminar and turbulent flow there is an area
referred to as transitional flow where conditions are
unstable and have a blend of each characteristic.
Laminar Flow
This is sometimes known as streamline, viscous or
steady flow. The fluid moves through the pipe in con-
centric layers with the maximum velocity in the centre
of the pipe, decreasing to zero at the pipe wall.
The velocity profile is parabolic, the gradient of which
depends upon the viscosity of the fluid for a set flow-
rate as shown in Fig. 2.1.7a.
u
max
V
Parabolic curve
u
max = Maximum Velocity
V = Velocity
u
max
V
u
max = Maximum Velocity
V = Velocity
Fig. 2.1.7a Laminar flow Fig. 2.1.7b Turbulent flow
22
2.0
Terminology
and
Theory

Reynolds Number (Re)
Reynolds number for pipe flow is given by equation as
follows:
This is a ratio of inertia forces to viscous
forces, and as such, a useful value for
determining whether flow will be laminar
or turbulent.
Re = D x V x ρ
µ
Where:
D = Tube Diameter (m)
ρ = Density (kg/m3
)
µ = Absolute Viscosity (Pas)
Re = D x V x ρ
µ
Where:
ρ = Density (kg/m3
)
µ = Absolute Viscosity (cP)
or
Re = 21230 x Q
D x µ
Where:
Q = Capacity (l/min)
or
Re = 3162 x Q
D x ν
Where:
ν = Kinematic Viscosity (cSt)
or
Re = 3800 x Q
D x ν
Where:
23
2.0
Terminology
and
Theory

Since Reynolds number is a ratio of two forces, it
has no units. For a given set of flow conditions, the
Reynolds number will not vary when using different
units. It is important to use the same set of units, such
as show on previous page, when calculating Reynolds
numbers.
Where transitional flow occurs, frictional loss calcula-
tions should be carried out for both laminar and turbu-
lent conditions, and the highest resulting loss used in
subsequent system calculations.
Re less than 2300 - Laminar Flow
(viscous force dominates
- high system losses)
Re in range 2300 to 4000 - Transitional Flow
(critically balanced forces)
Re greater than 4000 - Turbulent Flow
(inertia force dominates
- low system losses)
2.0
Terminology
and
Theory

2.1.8 Vapour Pressure
Fluids will evaporate unless prevented from doing so
by external pressure (Fig. 2.1.8a). The vapour pressure
of a fluid is the pressure (at a given temperature) at
which a fluid will change to a vapour and is expressed
as absolute pressure (bar a or PSIA) - see section
2.2.2. Each fluid has its own vapour pressure/temper-
ature relationship. In pump sizing, vapour pressure can
be a key factor in checking the Net Positive Suction
Head (NPSH) available from the system (see section
2.2.4).
Temperature Vapour pressure (bar)
0º C (32º F) 0.006 bar a (0.087 PSIA)
20º C (68º F) 0.023 bar a (0.334 PSIA)
100º C (212º F) 1.013 bar a (14.7 PSIA)
Water will boil (vaporise) at a temperature of:
• 0° C (32° F) if Pvp = 0.006 bar a (0.087 PSIA)
(atmospheric conditions at sea level)
In general terms Pvp:
• Is dependent upon the type of fluid
• Increases at higher temperature
• Is of great importance to pump inlet conditions
• Should be determined from relevant tables
The Pvp for water at various temperatures is shown in
section 14.4.
2.1.9 Fluids Containing Solids
It is important to know if a fluid contains any particulate
matter and if so, the size and concentration. Special
attention should be given regarding any abrasive solids
with respect to pump type and construction, operating
speed, and shaft seals.
Size of solids is also important, as when pumping large
particles, the pump inlet should be large enough for
solids to enter the pump without ‘bridging’ the pump
inlet. Also, the pump should be sized so the cavity
created in the pump chamber by the pump elements is
of sufficient size to allow satisfactory pump operation.
Concentration is normally expressed as a percentage
by weight (W/W) or volume (V/V) or a combination of
both weight and volume (W/V).
Pvp = Vapour pressure
(external pressure required to maintain as a fluid)
Fluid (liquid form)
Fig. 2.1.8a Vapour pressure
25
2.0
Terminology
and
Theory

Atmospheric Pressure
The actual magnitude of the atmospheric pressure
varies with location and with climatic conditions. The
range of normal variation of atmospheric pressure near
the earth’s surface is approximately 0.95 to 1.05 bar
absolute (bar a) or 13.78 to 15.23 PSI gauge (PSIG). At
sea level the standard atmospheric pressure is 1.013
bar a or 14.7 PSI absolute (bar a or PSIA).
Gauge Pressure
Using atmospheric pressure as a zero reference,
gauge pressure is the pressure within the gauge that
exceeds the surrounding atmospheric pressure. It is a
measure of the force per unit area exerted by a fluid,
commonly indicated in units of bar g (bar gauge) or
PSIG (PSI gauge).
Absolute Pressure
Is the total pressure exerted by a fluid. It equals atmos-
pheric pressure plus gauge pressure, indicated in units
of bar a (bar absolute) or PSIA (PSI absolute).
Absolute Pressure =
Gauge Pressure + Atmospheric Pressure
Vacuum
This is a commonly used term to describe pressure
in a pumping system below normal atmospheric
pressure. This is a measure of the difference between
the measured pressure and atmospheric pressure
expressed in units of mercury (Hg) or units of PSIA.
14.7 PSIA = 760 mm Hg (30 in Hg)
0 PSIA = 0 mm Hg (0 in Hg)
2.2 Performance Data
2.2.1 Capacity (Flow Rate)
The capacity (or flow rate) is the volume of fluid or
mass that passes a certain area per time unit. This is
usually a known value dependent on the actual pro-
cess. For fluids the most common units of capacity are
litres per hour (l/h), cubic metres per hour (m3
/h) and
UK or US gallons per minute (gal/min). For mass the
most common units of capacity are kilogram per hour
(kg/h), tonne per hour (t/h) and pounds per hour (lb/h).
2.2.2 Pressure
Pressure is defined as force per unit area:
P = F
A
Where F is the force perpendicular to a surface and
A is the area of the surface (Fig. 2.2.2a).
In the SI system the standard unit of force is the
Newton (N) and area is given in square metres (m2
).
Pressure is expressed in units of Newtons per square
metre (N/m2
). This derived unit is called the Pascal
(Pa). In practice Pascals are rarely used and the most
common units of force are bar, pounds per square
inch (lb/in2
) or PSI, and kilogram per square centimetre
(kg/cm2
).
Conversion factors between units of pressure are
given in section 14.3.5.
Different Types of Pressure
For calculations involving fluid pressures, the meas-
urements must be relative to some reference pressure.
Normally the reference is that of the atmosphere and
the resulting measured pressure is called gauge pres-
sure. Pressure measured relative to a perfect vacuum
is called ‘absolute pressure’.
1
A
F = Force
1
Fig. 2.2.2a Pressure
26
2.0
Terminology
and
Theory

Inlet (Suction) Pressure
This is the pressure at which the fluid is entering
the pump. The reading should be taken whilst the
pump is running and as close to the pump inlet as
possible. This is expressed in units of absolute bar a
(PSIA) or gauge bar g (PSIG) depending upon the inlet
conditions.
Outlet (Discharge) Pressure
This is the pressure at which the fluid leaves the pump.
Again, this reading should be taken whilst the pump is
running and as close to the pump outlet as possible.
The reading is expressed in units of gauge bar (PSIG).
Differential Pressure
This is the difference between the inlet and outlet pres-
sures. For inlet pressures above atmospheric pressure
the differential pressure is obtained by subtracting
the inlet pressure from the outlet pressure. For inlet
pressures below atmospheric pressure the differential
pressure is obtained by adding the inlet pressure to
the outlet pressure. It is therefore the total pressure
reading and is the pressure against which the pump
will have to operate. Power requirements are to be
calculated on the basis of differential pressure (Fig.
2.2.2b).
Example: Inlet Pressure above Atmospheric Pressure
Example: Inlet Pressure below Atmospheric Pressure
Outlet
4 bar g
(58 PSIG)
0 bar g
(0 PSIG)
0 bar g
(0 PSIG)
1.013 bar a
(14.7 PSIA)
2.513 bar a
(36.45 PSIA)
- =
5.013 bar a
(72.7 PSIA)
1.013 bar a
(14.7 PSIA)
1.5 bar g
(21.75 PSIG)
0 bar a
(0 PSIA)
Inlet Differential
Differential = 4 - 1.5 = 2.5 bar
or
= 58 - 21.75 = 36.25 PSI
Outlet Inlet Differential
+ =
4 bar g
(58 PSIG)
0 bar g
(0 PSIG)
5.013 bar a
(72.7 PSIA)
1.013 bar a
(14.7 PSIA)
0 bar a
(0 PSIA)
0 bar g
(0 PSIG)
0 bar a
(0 PSIA)
1.013 bar a
(14.7 PSIA)
0.5 bar a
(7.25 PSIA) Differential = 4 + (1.013 - 0.5) = 4.513 bar
or
= 58 + (14.7 -7.25) = 65.45 PSI
Fig. 2.2.2b Differential pressure
27
2.0
Terminology
and
Theory

The relationship of eleva-
tion equivalent to pressure
is commonly referred to as
‘head’.
The Relationship Between Pressure and Elevation
In a static fluid (a body of fluid at rest) the pressure
difference between any two points is in direct propor-
tion only to the vertical distance between the points.
The same vertical height will give the same pressure
regardless of the pipe configuration in between (Fig.
2.2.2c).
This pressure difference is due to the weight of a
‘column’ of fluid and can be calculated as follows:
Static Pressure (P) = ρ x g x h Where:
P = Pressure/Head (Pa)
ρ = Fluid Density (kg/m3
)
g = Gravity (m/s2
)
h = Height of Fluid (m)
Static Pressure (P) = h x SG
10
Where:
SG = Specific Gravity (bar)
or
Static Pressure (P) = h x SG
2.31
Where:
SG = Specific Gravity (PSI)
h = Height of Fluid (ft)
H
Fig. 2.2.2c Relationship of pressure to
elevation
2.0
Terminology
and
Theory

A pump capable of delivering 35 m (115 ft) head will
produce different pressures for fluids of differing
specific gravities (Fig. 2.2.2d).
A pump capable of delivering 3.5 bar (50 PSI) pressure
will develop different amounts of head for fluids of
differing specific gravities (Fig. 2.2.2e).
The following are terms commonly used to express
different conditions in a pumping system which can be
expressed as pressure units (bar or PSI) or head units
(m or ft).
Flooded Suction
This term is generally used to describe a positive inlet
pressure/head, whereby fluid will readily flow into the
pump inlet at sufficient pressure to avoid cavitation
(see section 2.2.3).
Static Head
The static head is a difference in fluid levels.
Static Suction Head
This is the difference in height between the fluid level
and the centre line of the pump inlet on the inlet side
of the pump.
Static Discharge Head
This is the difference in height between the fluid level
and the centre line of the pump inlet on the discharge
side of the pump.
Total Static Head
The total static head of a system is the difference
in height between the static discharge head and the
static suction head.
Friction Head
This is the pressure drop on both inlet and discharge
sides of the pump due to frictional losses in fluid flow.
Dynamic Head
This is the energy required to set the fluid in motion
and to overcome any resistance to that motion.
SG 1.0
35
m
(115
ft)
Water
3.5 bar
(50 PSI) SG 1.4
35
m
(115
ft)
Slurry
4.9 bar
(70 PSI) SG 0.7
35
m
(115
ft)
Solvent
2.5 bar
(35 PSI)
SG 1.0
35
m
(115
ft)
Water
3.5 bar
(50 PSI) SG 1.4
25
m
(82
ft)
Slurry
3.5 bar
(50 PSI) SG 0.7
50
m
(165
ft)
Solvent
3.5 bar
(50 PSI)
Fig. 2.2.2d Relationship of elevation to
pressure
Fig. 2.2.2e Relationship of elevation to
pressure
29
2.0
Terminology
and
Theory

Total Suction Head
The total suction head is the static suction head less
the dynamic head. Where the static head is negative,
or where the dynamic head is greater than the static
head, this implies the fluid level will be below the centre
line of the pump inlet (i.e., suction lift).
Total Discharge Head
The total discharge head is the sum of the static
discharge and dynamic heads.
Total Head
Total head is the total pressure difference between the
total discharge head and the total suction head of the
pump. The head is often a known value. It can be cal-
culated by means of different formulas if the installation
conditions are specified.
Total Head H = Ht - (± Hs)
Total Discharge Head Ht = ht + hft + Pt
Total Suction Head Hs = hs - hfs + (± Ps)
Where:
H = Total head
Hs = Total suction head
Ht = Total discharge head
hs = Static suction head
ht = Static discharge head
hfs = Pressure drop in suction line
hft = Pressure drop in discharge line
Ps = Vacuum or pressure in a tank
on suction side
Pt = Pressure in a tank on discharge side
In general terms:
p > 0 for pressure
p < 0 for vacuum
p = 0 for open tank
hs > 0 for flooded suction
hs < 0 for suction lift
hfs
hft
h
t
h
s
hfs
hft
h
t
h
s
hfs
hft
Pt
h
t
h
s
hfs
hft
h
t
h
s
Pt
Fig. 2.2.2f Flooded suction and open discharge
tanks
Fig. 2.2.2h Suction lift and open discharge tanks
Fig. 2.2.2g Flooded suction and closed discharge tanks
Fig. 2.2.2i Suction lift and closed discharge tanks
30
2.0
Terminology
and
Theory

Pressure drop is the result of
frictional losses in pipework,
fittings and other process
equipment etc.
Pressure Drop
Manufacturers of processing equipment, heat ex-
changers, static mixers etc., usually have data available
for pressure drop. These losses are affected by fluid
velocity, viscosity, tube diameter, internal surface finish
of tube and tube length.
The different losses and consequently the total pres-
sure drop in the process are, if necessary, determined
in practice by converting the losses into equivalent
straight length of tube which can then be used in
subsequent system calculations.
Viscosity - cP 1 - 100 101 - 2000 2001 - 20,000 20,001 - 100,000
Correction Factor 1.0 0.75 0.5 0.25
For calculations on water like viscosity fluids, the pres-
sure drop can be determined referring to the Pressure
Drop Curve (see section 14.5) as shown in Example
1. For higher viscosity fluids, a viscosity correction
factor is applied to the tube fittings by multiplying the
resultant equivalent tube length by the figures shown in
table 2.2.2a below - see Example 2.
Table 2.2.2a
31
2.0
Terminology
and
Theory

Example 1 Process:
Pumping milk from tank A to tank G
Q = 8 m3
/h (35 US gal/min) (Fig. 2.2.2j).
Tubes, valves, and fittings:
A: Tank outlet dia. 63.5 mm (2.5 in)
A-B: 4 m (13 ft) tube dia. 63.5 mm (2.5 in)
A-B: 1 off bend 90° dia. 63.5 mm (2.5 in)
B-C: 20 m (66 ft) tube dia. 51 mm (2 in).
C: Unique SSV standard ISO 51 mm
C-E: 15 m (49 ft) tube dia. 51 mm (2 in)
B-E: 3 off bend 90° dia. 51 mm (2 in)
D: Non-return valve type LKC-2, 51 mm (2 in)
E: Unique SSV standard ISO 51 mm
E-F: 46 m (151 ft) tube dia. 38 mm (1.5 in)
E-F: 4 off bend 90° dia. 38 mm (1.5 in)
F: Seat valve type SRC-W-38-21-100
The pressure drop through the tubes, valves and
fittings is determined as equivalent tube length, so that
the total pressure drop can be calculated.
The conversion into equivalent tube length is carried
out by reference to chapter 14.7. This results in the
following equivalent tube length for the different equip-
ment as shown in the following tables:
Equipment Equivalent ISO Tube Length (m)
38 mm 51 mm 63.5 mm
A Tank outlet 1 (estimated)
A-B Tube 4
A-B Bend 90° 1 x 1
B-C Tube 20
C-E Tube 15
C-E Unique SSV standard ISO 11
B-E Bend 90° 3 x 1
D LKC-2 non-return valve 12
E Unique SSV standard ISO 11
E-F Tube 46
E-F Bend 90° 4 x 1
F Unique SSV standard ISO 6
Total 56 72 6
Table 2.2.2b
G
E
D
C
B
A
F
Fig. 2.2.2j Example
32
2.0
Terminology
and
Theory

Equipment Equivalent ISO Tube Length (ft)
1.5 in 2 in 2.5 in
A Tank outlet 3 (estimated)
A-B Tube 13
A-B Bend° 1 x 3
B-C Tube 66
C-E Tube 49
C-E Unique SSV standard ISO 36
B-E Bend° 3 x 3
D LKC-2 non-return valve 39
E Unique SSV standard ISO 36
E-F Tube 151
E-F Bend° 4 x 3
F Unique SSV standard ISO 20
Total 183 235 19
Table 2.2.2c
As viewed from the prior tables the pressure drop
through the different equipment corresponds to the
following equivalent tube length.
38 mm (1.5 in) tube: Length = 56 m (184 ft)
51 mm (2 in) tube: Length = 72 m (236 ft)
63.5 mm (2.5 in) tube: Length = 6 m (20 ft)
The pressure drop through 100 m of tube for sizes 38
mm, 51 mm and 63.5 mm is determined by means of
the following curve, also shown in 14.5 (Fig. 2.2.2k).
33
2.0
Terminology
and
Theory

The total pressure drop ∆H in the process is conse-
quently calculated as follows:
38 mm: ∆H = 56 x 13.2 = 7.39 m
100
51 mm: ∆H = 72 x 3.0 = 2.16 m
100
63.5 mm: ∆H = 6 x 1.1 = 0.07 m
100
∆H = 7.39 + 2.16 + 0.07 = 9.62 m ≈ 9.6 m (≈ 1 bar)
or
1.5 in: ∆H = 183 x 43 = 24.0 ft
328
2 in: ∆H = 235 x 10 = 7.2 ft
328
2.5 in: ∆H = 19 x 4 = 0.2 ft
328
∆H = 24.0 + 7.2 + 0.2 = 30.7 ft ≈ 31.4 ft (≈ 14 PSI)
A
0.1
0.1
1 10
Q = 8 m3
/h 100
1
~ 1.1
~ 3.0
~ 13.2
10
100
Pressure drop (m) Pressure drop in 100 m ISO/DIN tube (water at 20º C)
1000
Capacity (m3
/h)
B
C
D
E F
G
H
I
J
K
L
M
N
A = 25 mm
B = DN25
C = 38 mm
G = 63.5 mm
H = DN65
I = 76 mm
J = DN80
K = 101.6 mm
L = DN100
D = DN40
E = 61 mm
F = DN50
M = DN125
N = DN150
Note: A, C, E, G, I and K refer to ISO Tube - B, D, F, H, J, L, M and N refer to DIN Tube
Fig. 2.2.2k Pressure drop curve
34
2.0
Terminology
and
Theory

Fittings Equivalent ISO Tube Length (ft)
2 in 3 in
Non-return valve 2 x 39
Bend 90° 6 x 3
Bend 90° 4 x 3
Tee 3 x 10
Total 126 12
Table 2.2.2e
Example 2 Process:
Pumping glucose with a viscosity of 5000 cP from a
flooded suction through discharge pipeline as follows.
Tubes, valves and fittings:
30 m (98 ft) tube dia. 51 mm (2 in)
20 m (66 ft) tube dia. 76 mm (3 in)
2 off Non-return valves 51 mm (2 in)
6 off Bend 90° dia. 51 mm (2 in)
4 off Bend 90° dia. 76 mm (3 in)
3 off Tee (out through side port) 51 mm (2 in)
The pressure drop through the tubes, valves and
fittings is determined as equivalent tube length so that
the total pressure drop can be calculated.
For the pipe fittings the conversion into equivalent tube
length is carried out by reference to tables 14.7. This
results in the following equivalent tube length for the
different fittings as shown below:
Fittings Equivalent ISO Tube Length (m)
51 mm 76 mm
Non-return valve 2 x 12
Bend 90° 6 x 1
Bend 90° 4 x 1
Tee 3 x 3
Total 39 4
Table 2.2.2d
As viewed from the prior tables the pressure drop
through the different fittings corresponds to the
following equivalent tube length.
Tube dia. 51 mm (2 in): Length = 39 m (128 ft)
Tube dia. 76 mm (3 in): Length = 4 m (13 ft)
Applying the viscosity correction factor from table
2.2.2a for 5000 cP the equivalent tube length is now:
Tube dia. 51 mm (2 in):
Length = 39 m (126 ft) x 0.5 = 19.5 m (64 ft)
Length = 4 m (12 ft) x 0.5 = 2 m (7 ft)
These figures of 19.5 m (64 ft) and 2 m (7 ft) would
be added to the straight tube lengths given as shown
above, and subsequently used in calculating the dis-
charge pressure at the flow rate required.
30 m (98 ft) + 19.5 m (63 ft) = 49.5 m (162 ft)
+
20 m (66 ft) + 2 m (7 ft) = 22 m (72 ft)
35
2.0
Terminology
and
Theory

Friction Loss Calculations
Since laminar flow is uniform and predictable it is the
only flow regime in which the friction losses can be
calculated using purely mathematical equations. In
the case of turbulent flow, mathematical equations are
used, but these are multiplied by a co-efficient that is
normally determined by experimental methods. This
co-efficient is known as the Darcy friction factor (fD).
The friction losses in a pipework
system are dependent upon the
type of flow characteristic that is
taking place. The Reynolds number
(Re) is used to determine the flow
characteristic, see section 2.1.7.
The Miller equation given below can be used to deter-
mine the pressure loss due to friction for both laminar
and turbulent flow in a given length of pipe (L).
Pf = fD x L x ρ x V2
D x 2
Where:
Pf = Pressure Loss due to Friction (Pa)
fD = Darcy Friction Factor
L = Tube Length (m)
)
Pf = 5 x SG x fD x L x V²
D
Where:
Pf = Pressure Loss due to Friction (bar)
fD
= Darcy Friction Factor
L = Tube Length (m)
SG = Specific Gravity
or
Pf = 0.0823 x SG x fD x L x V2
D
Where:
Pf = Pressure Loss due to Friction (PSI)
fD = Darcy Friction Factor
L = Tube Length (ft)
For laminar flow, the Darcy friction factor (fD) can be
calculated directly from the equation:
fD = 64
Re
36
2.0
Terminology
and
Theory

The relative roughness of pipes
varies with diameter, type of material
used and age of the pipe. It is usual
to simplify this by using a relative
roughness (k) of 0.045 mm, which
is the absolute roughness of clean
commercial steel or wrought iron
pipes as given by Moody.
The term cavitation is derived from
the word cavity, meaning a hollow
space.
For turbulent flow, the Darcy friction factor (fD) has to
be determined by reference to the Moody diagram
(see section 14.8). It is first necessary to calculate the
relative roughness designated by the symbol E.
Where:
E = k
D
k = relative roughness which is the average heights of
the pipe internal surface peaks (mm)
D = internal pipe diameter (mm)
2.2.3 Cavitation
Cavitation is an undesirable vacuous space in the inlet
port of the pump normally occupied by fluid. The low-
est pressure point in a pump occurs at the pump inlet
- due to local pressure reduction part of the fluid may
evaporate generating small vapour bubbles. These
bubbles are carried along by the fluid and implode
instantly when they get into areas of higher pressure.
If cavitation occurs this will result in loss of pump
efficiency and noisy operation. The life of a pump can
be shortened through mechanical damage, increased
corrosion, and erosion when cavitation is present.
37
2.0
Terminology
and
Theory

When sizing pumps on highly viscous fluids care must
be taken not to select too higher pump speed so as
to allow sufficient fluid to enter the pump and ensure
satisfactory operation.
For all pump application problems, cavitation is the
most commonly encountered. It occurs with all types
of pumps, centrifugal, rotary, or reciprocating. When
found, excessive pump speed and/or adverse suction
conditions will probably be the cause and reducing
pump speed and/or rectifying the suction condition
will usually eliminate this problem.
Cavitation should be avoided
at all costs.
2.2.4 Net Positive Suction Head (NPSH)
In addition to the total head, capacity, power and
efficiency requirements, the condition at the inlet of
a pump is critical. The system on the inlet side of the
pump must allow a smooth flow of fluid to enter the
pump at a sufficiently high pressure to avoid cavitation
(Fig. 2.2.4a).
This is called the Net Positive Suction Head, generally
abbreviated NPSH.
Pump manufacturers supply data about the net posi-
tive suction head required by their pumps (NPSHr) for
satisfactory operation. When selecting a pump, it is
critical the net positive suction head available (NPSHa)
in the system is greater than the net positive suction
head required by the pump.
For satisfactory pump operation:
NPSHa > NPSHr
N.I.P.A. > N.I.P.R.
NPSHa is also referred to as N.I.P.A. (Net Inlet
Pressure Available) and NPSHr is also referred to as
N.I.P.R. (Net Inlet Pressure Required).
A simplified way to look at NPSHa or N.I.P.A. is to
imagine a balance of factors working for (static pres-
sure and positive head) and against (friction loss and
vapour pressure) the pump.
Providing the factors acting for the pump outweigh
those factors acting against, there will be a positive
suction pressure.
For
Against
-
+
Fig. 2.2.4a NPSH balance
38
2.0
Terminology
and
Theory

The value of NPSHa or N.I.P.A. in the system is
dependent upon the characteristic of the fluid being
pumped, inlet piping, the location of the suction vessel,
and the pressure applied to the fluid in the suction
vessel. This is the actual pressure seen at the pump in-
let. It is important to note, it is the inlet system that sets
the inlet condition and not the pump. It is calculated as
shown above in Figure 2.2.4b.
It is important the units used for calculating NPSHa or
N.I.P.A. are consistent i.e., the total figures should be
in m or ft.
For low temperature applications the vapour pressure
is generally not critical and can be assumed to be
negligible.
NPSHa or
N.I.P.A.
= Pa ± hs - hfs - Pvp Where:
Pa = Pressure absolute above fluid level (bar)
hs = Static suction head (m)
hfs = Pressure drop in suction line (m)
Pvp = Vapour pressure (bar a)
or
Where:
Pa = Pressure absolute above fluid level (PSI)
hs = Static suction head (ft)
hfs = Pressure drop in suction line (ft)
Pvp = Vapour pressure (PSIA)
Fig. 2.2.4b NPSH calculation
hs
Pressure action on
surface of liquid (Pa)
NPSHa =
or N.I.P.A.
Static suction
head (hs)
Pressure drop
(hfs)
Vapour pressure
(Pvp)
± - -
+ve -ve +ve -ve
39
2.0
Terminology
and
Theory

Example 1 Process:
Example 2 Process:
Water at 50° C (122° F)
Pa = Pressure Absolute above Fluid Level (1 bar = 10 m)
(14.7 PSI = 33.9 ft)
hs = Static Suction Head (3.5 m)
(11.5 ft)
hfs = Pressure Drop in Suction Line (1.5 m)
(5 ft)
Pvp = Vapour Pressure (0.12 bar a = 1.2 m)
(1.8 PSIA = 4 ft)
NPSHr of pump selected = 3.0 m (10 ft)
NPSHa = Pa - hs - hfs - Pvp = Pa - hs - hfs - Pvp
= 10 - 3.5 - 1.5 - 1.2 (m) or = 33.9 - 11.5 - 5 - 4 (ft)
= 3.8 m = 13.4 ft
As NPSHa is greater than NPSHr, no cavitation will occur under the conditions stated (Fig. 2.2.4c).
Water at 75° C (167° F)
Pa = Pressure Absolute above Fluid Level (0.5 bar = 5 m)
(7 PSI = 16 ft)
(5 ft)
hfs = Pressure Drop in Suction Line (1.0 m)
(3 ft)
Pvp = Vapour Pressure (0.39 bar a = 3.9 m)
(5.7 PSIA = 13 ft)
NPSHr of pump selected = 3 m (10 ft)
NPSHa = Pa + hs - hfs - Pvp = Pa + hs - hfs - Pvp
= 5 + 1.5 - 1 - 3.9 (m) or = 16 + 5 - 3 - 13 (ft)
= 1.6 m = 5 ft
As NPSHa is less than NPSHr, cavitation will occur under the conditions stated (Fig. 2.2.4d).
hfs = 1.5 m
Pa = 1 bar
(open tank)
3.5
m
hfs = 1 m
Pa = 0.5 bar
(vacuum)
1.5
m
Fig. 2.2.4c Example 1 Fig. 2.2.4d Example 2
40
2.0
Terminology
and
Theory

Example 3 Process:
Glucose at 50° C (122° F)
Pa = Pressure Absolute above Fluid Level (1 bar = 10 m)
(14.7 PSI = 33.9 ft)
(5 ft)
hfs = Pressure Drop in Suction Line (9 m)
(29.5 ft)
Pvp = Vapour Pressure (assumed negligible = 0 m)
(0 ft)
NPSHr of pump selected = 3 m (10 ft)
NPSHa = Pa + hs - hfs - Pvp = Pa + hs - hfs - Pvp
= 10 + 1.5 - 9 - 0 (m) or = 32.8 + 5 - 29.5 - 0 (ft)
= 2.5 m = 8.2 ft
As NPSHa is less than NPSHr, cavitation will occur under the conditions stated (Fig. 2.2.4e).
hfs
h
s
Pa
Fig. 2.2.4e Example 3
41
2.0
Terminology
and
Theory

From the NPSHa formula it is possible to check and
optimise the conditions which affect NPSHa.
The effects are shown in Fig. 2.2.4f - Fig. 2.2.4k
Flooded
inlet
h
s
Lift
h
s
Bend
Filter
Tee
Valve Pressure
drops
Pressure
Pa >1
Vacuum
Pa<1
Vapour pressure
(Temperature dependent)
Fig. 2.2.4f Positive effect
Fig. 2.2.4h Negative effect
Fig. 2.2.4j Negative effect
Fig. 2.2.4g Positive effect
Fig. 2.2.4i Negative effect
Fig. 2.2.4k Negative effect
2.0
Terminology
and
Theory

Suggestions for avoiding cavitation:
• Keep pressure drop in the inlet line to a minimum
i.e., length of line as short as possible, diameter as
large as possible, and minimal use of pipe fittings
such as tees, valves etc.
• Maintain a static head as high as possible
• Reduce fluid temperature, although caution is
needed as this may have an effect of increasing
fluid viscosity, thereby increasing pressure drop
2.2.5 Pressure ‘Shocks’ (Water Hammer)
The term ‘shock’ is not strictly correct as shock waves
only exist in gases. The pressure shock is really a
pressure wave with a velocity of propagation much
higher than the velocity of the flow, often up to 1400
m/s for steel tubes. Pressure waves are the result of
rapid changes in the velocity of the fluid in especially in
long runs of piping.
The following causes changes in fluid velocity:
• Valves are closed or opened
• Pumps are started or stopped
• Resistance in process equipment such as valves,
filters, metres, etc.
• Changes in tube dimensions
• Changes in flow direction
The major pressure wave problems in process plants
are usually due to rapidly closed or opened valves.
Pumps, which are rapidly/ frequently started or
stopped, can also cause some problems.
When designing pipework systems, it is important
to keep the natural frequency of the system as high
as possible by using rigid pipework and as many
pipework supports as possible, thereby avoiding the
excitation frequency of the pump.
Effects of pressure waves:
• Noise in the tube
• Damaged tube
• Damaged pump, valves, and other equipment
• Cavitation
Velocity of propagation
The velocity of propagation of the pressure wave
depends on:
• Elasticity of the tubes
• Elasticity of the fluid
• The tubes support
When for example, a valve is closed, the pressure
wave travels from the valve to the end of the tube. The
wave is then reflected back to the valve. These reflec-
tions are in theory continuing but in practice the wave
gradually attenuates cancelled by friction in the tube.
A pressure wave as a result of a pump stopping is
more damaging than for a pump starting due to the
large change in pressure which will continue much
longer after a pump is stopped compared to a pump
starting. This is due to the low fluid velocity which
results in a relatively small damping of the pressure
waves.
A pressure wave induced as a result of a pump
stopping can result in negative pressure values in long
tubes, i.e., values close to the absolute zero point
which can result in cavitation if the absolute pressure
drops to the vapour pressure of the fluid.
Precautions
Pressure waves are caused by changes in the velocity
of the liquid in especially long runs of tube. Rapid
changes in the operating conditions of valves and
pump are the major reasons to the pressure waves
and therefore, it is important to reduce the speed of
these changes.
There are different ways to avoid or reduce pressure
waves which are briefly described as follows:
43
2.0
Terminology
and
Theory

Correct flow direction
Incorrect flow direction through valves can induce
pressure waves particularly as the valve functions.
With air-operated seat valves incorrect direction of
flow can cause the valve plug to close rapidly against
the valve seat inducing pressure waves (Fig. 2.2.5a)
and Fig. 2.2.5b specify the correct and incorrect flow
direction for this type of valve.
Correct flow directions in the process plant can reduce
or even prevent pressure wave problems.
Damping of valves
The pressure wave induced by a seat valve can be
avoided or minimised by damping the movement of
the valve plug. The damping is carried out by means of
a special damper (see Fig. 2.2.5c).
Oil damper
Actuator
Correct
Incorrect
Fig. 2.2.5c Oil damper for seat valve
Fig. 2.2.5a Correct flow direction through seat
valve
Fig. 2.2.5b Incorrect flow direction through seat
valve
44
2.0
Terminology
and
Theory

Speed control of pumps
Speed control of a pump is a very efficient way to
minimise or prevent pressure waves. The motor is
controlled by means of a soft starter or a frequency
converter so that the pump is:
• Started at a low speed which is slowly increased
to duty speed
• Stopped by slowly decreasing from duty speed
down to a lower speed or zero
The risk of power failure should be taken into
consideration when using speed control against
pressure waves.
Equipment for industrial processes
There is various equipment available to reduce
pressure waves such as:
• Pressure storage tanks
• Pressure towers
• Damped or undamped non-return valves
These however, may not be suitable for hygienic
processes and further advice may be required before
they are recommended or used in such installations.
45
2.0
Terminology
and
Theory

This chapter gives an overview of the
pump technologies available from Alfa
Laval and how to determine which pumps
applies within various application areas.
Sustainable, hygienic and efficient pumps
As demand on processes increases, major factors
evolve to cater for an ever-growing population. The
quality of products and process profitability with an
increasing necessity for sustainability and “green”
initiatives, adds pressure for the correct selection
of a pump to the customer.
As a recognised market leader in pumping technol-
ogy, Alfa Laval has been at the forefront of supplying
sustainable, hygienic and efficient pumps to multiple
processes and applications for many years.
The pump is a critical part within a process and must
be able to carry out various duties under differing
conditions whilst returning economical value to the
user.
Some example conditions to consider:
• Transfer several types of fluids/products
• Gentle treatment of the fluids/products
• Overcome different losses and pressure drops
in the system
• Supply hygienic and long-lasting operation
• Optimal energy efficiency for sustainable use
• Ensure easy and safe installation, operation
and maintenance
Common pump issues can be:
• Incorrect type of pump for the intended application
• Incorrect design of the pump
• Incorrect selection of the pump according to duty
conditions, product data etc.
• Incorrect selection of shaft seals
• Incorrect choice of motor drives
46
3.0
Pump
Selection

Pump Selection
3.0
47
3.0
Pump
Selection

3.1 General Application Guide
The table shown below gives a general guide as to the various pump technology
within Alfa Laval that may be needed to suit the required application (Fig. 3.2a).
General
Requirements
Centrifugal Self-Priming
Centrifugal
Rotary Lobe Circumferential
Piston
Twin Screw
Product/Fluid
Requirements
Max. viscosity 800 cP 200 cP 1000000 cP 1000000 cP 1000000 cP
Max. pumping
temperature
140° C (284° F) 140° C (284° F) 200° C (392° F) 150° C (392° F) 150° C (392° F)
Min. pumping
temperature
- 10° C (14° F) - 10° C (14° F) - 20° C (-4° F) - 20° C (-4° F) - 20° C (-4° F)
Ability to pump abra-
sive products
Not
recommended
Not
recommended
Fair/Moderate Fair Fair/Moderate
Ability to pump fluids
holding air or gases
Not
recommended
Recommended Fair Moderate Recommended
Ability to pump shear
sensitive media
Fair Not
recommended
Recommended Recommended Recommended
Ability to pump solids
in suspension
Fair Not
recommended
Recommended Recommended Recommended
CIP/SIP capability
(sanitary)
Recommended Recommended Recommended Recommended Recommended
Dry running capa-
bility (when fitted
with flushed/quench
mechanical seals)
Self-draining capability Recommended Recommended Recommended Recommended Recommended
48
3.0
Pump
Selection

Performance Requirements
Max. capacity - m3
/hr 520 110 115 157 138
Max. Capacity - US
(United States) gal/min
2290 484 506 691 608
Max. discharge pres-
sure - bar
20 5.5 20 40 16
Max. discharge pres-
sure - psig
290 80 290 580 232
Ability to vary flow rate Fair Fair Recommended Recommended Recommended
Suction lift capability
(primed - wet)
Suction lift capability
(unprimed - dry)
Not
recommended
Recommended Fair Fair Fair
Drive Availability
Electric motor - direct
coupled
Yes Yes No No Yes
Electric motor - geared
reducer
No No Yes Yes Yes
Electric motor
- integrated inverter
(upon request)
Yes Yes Yes Yes Yes
Compliance with International
Standards and Guidelines
3-A Yes Yes Yes Yes Yes
FDA (Food and Drug
Administration)
Yes Yes Yes Yes Yes
EHEDG (European
Hygienic Equipment
Design Group)
Yes No Yes Yes Yes
United States
Pharmacopeia (USP)
Yes Yes Yes No No
Table 3.1a
49
3.0
Pump
Selection

Alfa Laval Pump Ranges
Fig. 3.2a Pump ranges
FM/GM
LKH
LKHex LKH Evap LKH UltraPure LKHI
LKH
Prime
i-Series
SolidC
Alfa Laval pumps
Standard duty With air
Demanding duty
Centrifugal
50
3.0
Pump
Selection

LKHPF
LKH
Multi-Stage
OptiLobe OS Twin Screw
Standard duty Demanding duty Versatile
SRU SX/SX UltraPure
DuraCirc/
DuraCirc Aseptic
Positive displacement
51
3.0
Pump
Selection

3.2 Pumps for Sanitary Applications
The following table illustrates which Alfa Laval pump ranges can be used in various sanitary
application areas. A detailed description of these pump ranges is given in chapter 4.
Brewery
Alfa Laval Centrifugal and Positive Displacement
pumps (PD) are used in most process stages of
brewing, from wort handling to beer pasteurisation
and filling. Generally, PD pumps best perform with
higher fluid viscosity applications, such as liquid
sugar tanker offloading and malt syrups, while low
fluid viscosity applications, such as beer and wa-
ter chilling, are mostly carried out using centrifugal
pumps.
Pump Type Pump Range Application Area
Brewery
Confectionary
Dairy
Prepared
Foods
Oils
/
Proteins
Pharmaceutical
Personal/Homecare
Soap
Beverages
Sugar
Water
Centrifugal
LKH         
LKH-Multistage         
LKHPF     
LKH Prime +
LKH Prime UP
     
LKHI        
LKH Evap       
LKH-Ultra Pure       
Solid C   
Rotary Lobe
SRU          
Optilobe        
SX + SX UP         
Circumferential Piston
DuraCirc         
DuraCirc Aseptic       
Twin Screw OS          
Table 3.2a
During the fermentation process, PD pumps such as
rotary lobe or twin screw, with their gentle pumping
action, are ideally used handling yeast holding delicate
cells.
Confectionery
Alfa Laval is a long-standing supplier of pumping
equipment to the confectionery industry, supplying
pumps to all the major companies. Alfa Laval PD
52
3.0
Pump
Selection

perfume, shampoo and blood products. Alfa Laval
offers a specialised UltraPure (UP) line for the pharma-
ceutical industry, comprising of both centrifugal and
rotary lobe pumps with industry leading documen-
tation packages and fully traceable, electropolished
components.
Personal/Homecare
Alfa Laval Centrifugal and Positive Displacement
pumps can be found on many applications within
this industry, handling products such as neat soap,
sulphonic acid, fabric conditioner, dishwash liquid,
fatty acid, SLES (Sodium Laureth Sulfate), CAPB
(Cocamidopropyl Betaine), liquid detergents and sur-
factants. The gentle transference and high efficiency
within Alfa Laval’s pump portfolio help maintain optimal
product integrity, keeping process time.
Beverages
Alfa Laval Centrifugal pumps are mainly used in
applications handling thin liquid sugar solutions,
water, soft drinks and flavourings. Alfa Laval Positive
Displacement pumps are mainly used for applications
handling fruit juice concentrates or wine to account for
higher viscosity media and gentle handling.
Sugar
Alfa Laval Positive Displacement pumps, with their
ability to handle highly viscous, abrasive products, can
be found within many areas of sugar refined prod-
ucts requiring hygienic handling, such as high boiled
sugars, glucose solutions and sugar syrups used in
confectionery, bakery and brewing.
Water
Alfa Laval Centrifugal pumps provide a low-cost effec-
tive solution for high purity water and water like appli-
cations seen within general or pharmaceutical use.
pumps are to be found in many confectionery pro-
cesses, where their reliable low shear flow character-
istics are ideally suited to the transfer of media such
as chocolate, glucose, biscuit cream and fondant.
Circumferential piston pumps offer excellent NPSHr
characteristics for applications where NPSHa is
limited. Confectionery products that hold particulate
matter, such as fruit pie fillings, can be handled by Alfa
Laval’s complete positive displacement pump range.
Alfa Laval’s centrifugal pumps can be commonly found
in fat and vegetable oil applications.
Dairy
Alfa Laval’s whole pump portfolio, with their hygienic
construction and conforming to 3-A standards (see
chapter 11) with high efficiency and ease of service,
are used extensively throughout the dairy industry.
Alfa Laval’s pumps have been used in milk processing,
cream and cultured products such as yoghurt and
quark for over 50 years.
Prepared Food
Generally Alfa Laval Positive Displacement pumps can
be found on general transfer duties handling products
such as pet food, baby food, sauces and flavourings.
Alfa Laval’s highly efficient centrifugal pump range can
be found on products such as edible oils and soups
ranging in the medium to low viscosity.
Pharmaceutical
Alfa Laval Centrifugal and Rotary Lobe pumps can be
found on many applications within this industry where
hygiene and corrosion resistance is paramount, such
as cosmetic creams, protein solutions, toothpaste,
53
3.0
Pump
Selection

Pump selection for both Centrifugal and Positive
Displacement Pumps can be made using Alfa Laval’s
ALiCE program (Alfa Laval intelligent Configurator
Engine). This program prompts the user to enter pump
duty conditions and generates a list of pumps most
suited to their specific application. The program allows
for selection for the whole pump portfolio via dedicat-
ed selection tabs and can accompany up to 3 varying
duty conditions within calculations.
As well as performing the pump selection, ALiCE also
extracts data from a comprehensive rheological data-
base enabling it to suggest in-pump viscosity, Specific
Gravity, maximum operating speeds, elastomer
compatibility and primary seal configuration to users to
streamline the process.
The extensive rheology database contained within
ALiCE is based on rheological tests performed over
decades on end users’ liquids at Alfa Laval’s laborato-
ry and will be continually added as additional products
are tested.
After the pump has been selected, the user will be
aided to complete a pump unit design. This will include
a wide scope of specification options such as connec-
tion types, heating/cooling devices and ancillaries that
have been included in the program, driven by market
demand.
ALiCE offers insight to the noted duty conditions within
the ancillary section, detailing the operating speed, the
power absorbed, and torque required for each duty
3.3 ALiCE Configuration Tool
point and cross checking against any chosen motor
drive to ensure all points are covered. This provides
peace of mind to the user and ensures the most opti-
mal selection for both capital and energy consumption
costs.
After completion, the price of the pump will be dis-
played and its configuration code (item number) can
be generated, simplifying the quotation and/or order-
ing process for all users.
In addition, ALiCE will also provide a detailed parts list
for the pump with item numbers and recommended
service kits identified and priced. Dimensional details
in the form of general arrangement drawings can also
be generated within the software and sent to an email
of your choice.
A link to all technical information that may be needed
to go with the quotation such as Operation manuals,
generic or specific performance curves, and technical
data sheets can also be provided.
Flexibility has been built into the software to enable
specific enquiries to be answered without the need
to complete a full pump selection. For example,
recommended service kits can be extracted based
on an existing configuration code or direct access
to technical information relating to a specific pump
technology is also possible.
All information is offered for guidance purposes only.
If you would like access to the Alfa Laval
Configuration Tool, please contact your
local Alfa Laval sales company.
54
3.0
Pump
Selection

55
3.0
Pump
Selection

This chapter gives a description of Alfa Laval
pump ranges including design, principle of
operation and pump model types.
4.1 Centrifugal Pumps
4.1.1 General
The Alfa Laval range of Centrifugal Pumps has been
designed specially for use in the food, dairy, bever-
age, personal and home care, pharmaceutical and
light chemical industries. Centrifugal pumps including
self-priming, multi-stage and those for high inlet pres-
sure, can handle most low viscosity applications.
Attributes include:
• Hygienic and cleanable
• High efficiency
• Low power consumption
• Low noise level
• Low NPSH requirement
• Easy maintenance
56
4.0
Pump
Description

Pump Description
4.0
57
4.0
Pump
Description

The principle of the multi-stage centrifugal pump is
the same as the conventional centrifugal pump (Fig.
4.1.2b). The pump consists, however, of several impel-
lers (several stages) which further develop the pressure
from one stage to another but flow rate is unchanged.
The multi-stage centrifugal pump operates as if several
conventional centrifugal pumps are connected in
series.
4.1.3 Design
In general, the Alfa Laval Centrifugal Pump does not
contain many parts, with the pump head being con-
nected to an electric motor. The impeller is fixed onto
the pump shaft which is housed in a pump casing and
back plate – these components are described in the
following text:
The impeller has two or multiple vanes
depending on the type of centrifugal
pump. The impeller diameter and width
will vary dependent upon the duty
requirements.
Impeller
The impeller is of cast manufacture and semi-open
type i.e., the impeller vanes are open in front (Fig.
4.1.3a). This type allows visual inspection of the vanes
and the area between them. This design makes it easy
to clean and suitable for polishing.
4.1.2 Principle of Operation
Fluid is directed to the impeller eye and is forced into
a circular movement by the rotation of the impeller
vanes. As a result of this rotation, the impeller vanes
transfer mechanical work to the fluid in the impeller
channel, which is formed by the impeller vanes. The
fluid is then pressed out of the impeller by means of
centrifugal force and finally leaves the impeller channel
with increased pressure and velocity (Fig. 4.1.2a).
The velocity of the fluid is also partly converted into
pressure by the pump casing before it leaves the
pump through the outlet.
Fig. 4.1.3a Semi-open impeller
Fig. 4.1.2b Multistage centrifugal pump
Fig. 4.1.2a Principle of operation
58
4.0
Pump
Description

Pump Casing
The pump casing is of rigid steel manufacture,
complete with male screwed connections and
can be supplied with fittings or clamp liners (Fig.
4.1.3b).
The pump casing is designed for multi position outlet,
with 360° flexibility (Fig. 4.1.3c).
Back Plate
The back plate is of pressed steel manufacture, which
together with the pump casing form the actual fluid
chamber in which the fluid is transferred by means of
the impeller (Fig. 4.1.3d).
Mechanical Seal
The connection between the motor shaft/pump shaft
and the pump casing is sealed by means of a mechan-
ical seal, which is described in chapter 6.
Fig. 4.1.3b Pump casing Fig. 4.1.3c 360° flexibility
Fig. 4.1.3d Back plate
59
4.0
Pump
Description

Shroud and Legs
Most pump types are fitted with shrouds and adjust-
able legs (Fig. 4.1.3e). The shroud maybe insulated
to keep noise to a minimum and protect the motor
against damage.
Please note Alfa Laval Centrifugal Pumps for the US
market are supplied without shrouds in order to meet
3A requirements.
Pump Shaft/Connections
Most pumps have stub shafts that are fixed to the
motor shafts by means of compression couplings,
eliminating the use of keyways (Fig. 4.1.3f). The stub
shaft assembly design provides a simple, yet secure
method of drive that reduces vibration and noise.
On the multistage centrifugal pump, the length of the
pump shaft will differ depending upon the number of
impellers fitted.
Adaptor
The connection between the motor and back plate is
made by means of an adaptor, which can be attached
to any standard IEC or NEMA frame electric motor (Fig.
4.1.3g).
Fig. 4.1.3f Compression coupling
Fig. 4.1.3g Adaptor
Fig. 4.1.3e Pump with shroud and legs
60
4.0
Pump
Description

61
4.0
Pump
Description

The LKH range is available in thirteen sizes:
LKH-5, -10, -15, -20, -25, -35, -40, -45, -50, -60,
-70, -75 (US) (Fig. 4.1.4b), -85 and -90.
Suitable for inlet pressures up to 10 bar (145 PSIG) and
delivering flow rates for 50 Hz up to 500 m3
/hr (2200
US gal/min) and differential pressures up to 11.5 bar
(165 PSIG) and for 60 Hz, 16 bar (230 PSIG).
4.1.4 Pump Range
The Alfa Laval Centrifugal Pump portfolio comprises of
different ranges as follows:
LKH Range
The LKH pump is a highly efficient and economical
centrifugal pump, which meets the requirements of
hygienic and gentle product treatment and chemical
resistance (Fig. 4.1.4a).
The Alfa Laval LKH Centrifugal Pump is suited to
demanding applications in a variety of industries such
as dairy, food, beverage, home and personal care and
additional chemical industries.
Fig. 4.1.4b LKH (US version)
Fig. 4.1.4a LKH
62
4.0
Pump
Description

LKH Evap Range
The Alfa Laval LKH Evap Centrifugal Pump is suit-
ed to evaporation type applications within the dairy,
food, beverage, brewery, alcohol, ethanol, starch and
chemical industries (Fig. 4.1.4c - 4.1.4d). As a low-NP-
SHr, high efficiency centrifugal pump, the LKH Evap is
a tailored evaporator pump supported by strong and
extensive documentation.
It is ideal for use in evaporation duties for applications,
such as liquid concentration and powder processing
as well as plant and equipment dewatering.
Additional port sizing options compared to standard
LKH on some models provide for an improved suction
performance, vital to applications where NPSHa is
limited.
It features a special scraper impeller option, ClearFlow,
that solves the product build-up problem in high solids
applications, which can prolong production time be-
tween cleaning (Fig. 4.1.4e).
The LKH Evap pump is available in ten sizes, LKH
Evap-10, -15, -20, -25, -35, -40, -45, -50, -60 and -70.
Flow rates for 50 Hz up to 280 m3
/hr (1233 US gal/
min) and differential pressures up to 10 bar (145 PSIG)
and for 60 Hz up to 280 m3
/hr (1233 US gal/min) and
differential pressure up to 16 bar (230 PSIG).
Fig. 4.1.4c LKH Evap Fig. 4.1.4d LKH Evap (US version)
Fig. 4.1.4e Clearflow impeller
63
4.0
Pump
Description

LKHex Range
These pumps derived from the standard LKH are
designed to meet the requirements of the ATEX
directive 2014/34/EU group II, category 2G, temper-
ature class T3 and T4 and can be used in potentially
explosive environments (Fig. 4.1.4f).
The LKHex pump is available in 10 sizes, LKHex-10,
-15, -20, -25, -35, -40, -45, -50, -60 and -70.
/hr (1233 US gal/
This range is also available in an UltraPure version with
the exception of LKHex-15 and -50.
LKH UltraPure Range
The Alfa Laval LKH UltraPure pump is designed
to meet the stringent demands and regulations of
high-purity applications across the biotechnology and
pharmaceutical industries which require equipment
with the highest material integrity (Fig. 4.1.4g - 4.1.4h).
Designed in accordance with ASME BPE and GMP,
this pump range complies with the stringent require-
ments necessary for validation, qualification and
process control providing consumer safety.
Typically supplied with a 45° casing outlet to ensure it
is self-venting and options of improved surface finishes
to prevent biofilm build up.
All pumps are delivered with a complete Alfa Laval
Q-doc documentation package including material
traceability. Q-doc provides easier validation, proof
of origin and compliance for inspection according to
Good Manufacturing Practice (GMP) and ASME BPE
requirements.
The LKH-UltraPure range is available in eight sizes,
LKH-UltraPure-10, -20, -25, -35, -40, -45, -60 and -70.
Flow rates up to 280 m3
differential pressures for 50 Hz up to 10 bar (145 PSIG)
and for 60 Hz, 16 bar (230 PSIG).
Fig. 4.1.4f LKHex
Fig. 4.1.4g LKH-UltraPure Fig. 4.1.4h LKH-UltraPure (US version)
64
4.0
Pump
Description

LKHI Range
This pump range is similar to the LKH range but is
suitable for inlet pressures up to 16 bar (230 PSIG).
The pump can withstand this high inlet pressure due
to being fitted with an internal shaft seal (Fig. 4.1.4i
- 4.1.4j).
The LKHI range is available in nine sizes, LKHI-10, -15,
-20, -25, -35, -40, -45, -50 and -60.
/hr (1056 US gal/min)
with differential pressures up to 8 bar (115 PSIG). For
60 Hz, flow rates up to 275 m3
with differential pressures up to 11 bar (160 PSIG).
LKH Multistage Range
These pumps are primarily used in applications with
high outlet pressure and low capacity requirements
such as breweries, reverse osmosis and ultra-filtration.
The pumps are available as two, three or four stage
models (i.e., pumps fitted with two, three or four impel-
lers respectively - Fig. 4.1.4k - 4.1.4.l).
and discharge pressures up to 40 bar (580 PSIG) with
boost pressures up to 19 bar (275 PSIG) and for 60 Hz
up to 80 m3
/hr (352 US gal/min) and boost pressures
up to 26 bar (375 PSIG).
For inlet pressures greater than 10 bar (145 PSIG)
a ‘special’ motor is used incorporating fixed angular
contact bearings due to axial thrust.
The LKH Multistage range is available in six sizes
Pump Size Number of
stages
Pump Size Number of
stages
LKH-112 2 LKH-122 2
LKH-113 3 LKH-123 3
LKH-114 4 LKH-124 4
Fig. 4.1.4k LKH-Multistage Fig. 4.1.4l LKH-Multistage (US version)
Fig. 4.1.4j LKHI (US version)
Fig. 4.1.4i LKHI
65
4.0
Pump
Description

LKHPF High Pressure Range
These pumps are designed to handle high inlet
pressures built with reinforced pump casing and back
plate. Application areas include reverse osmosis mo-
no-filtration and ultra-filtration (Fig. 4.1.4m - 4.1.4n).
The LKHPF-High Pressure range is available in nine siz-
es, LKHP-10, -20, -25, -35, -40, -45, -50, -60 and -70.
The pump range is designed for inlet pressures up to
40 bar (580 PSIG). Flow rates for 50 Hz up to 280 m3
/
hr (1233 US gal/min) with differential pressures up to
10 bar (145 PSIG) and for 60 Hz, differential pressures
up to 16 bar (230 PSIG).
For these high inlet pressures a ‘special’ motor with
fixed angular contact bearings is used due to axial
thrust.
Fig. 4.1.4m LKHPF-High Pressure Fig. 4.1.4n LKHPF-High Pressure (US version)
66
4.0
Pump
Description

SolidC Range
The SolidC is the all-purpose Alfa Laval centrifugal
pump for less demanding applications (Fig. 4.1.4o
- 4.1.4p).
Designed for Cleaning-in-Place (CIP), it is ideal for
basic duties across the dairy, food, beverage and
personal care industries in which hygienic treatment
is required. Typical applications are pumping of CIP
solutions, utilities, cooling or heating water, and other
simple transport duties.
The SolidC range is available in four sizes, SolidC-1, -2,
-3 and -4.
Suitable for inlet pressures up to 4 bar (58 PSIG) and
delivering flow rates for 50 Hz up to 75 m3
/hr (330 US
gal/min) with differential pressures up to 8 bar (115
PSIG) and for 60 Hz, 11.5 bar (167 PSIG).
Fig. 4.1.4o SolidC Fig. 4.1.4p SolidC (US version)
67
4.0
Pump
Description

LKH Prime Range
Based on the Alfa Laval LKH pump, the Alfa Laval LKH
Prime centrifugal pump is a versatile, highly efficient
self-priming pump for use in hygienic applications,
especially tank emptying and CIP return applications
(Fig. 4.1.4q - 4.1.4r). With its combination of airscrew
technology and advanced design, the pump can
remove air or gas from the suction pipe.
The LKH Prime pump is designed to meet the strin-
gent hygienic requirements across the food, dairy,
beverage, and home-personal care industries. With
verified and effective CIP cleanability, the LKH Prime
can be used as a product pump as well.
The design of the LKH Prime is principally the same as
LKH but with an additional priming chamber, airscrew
and recirculation pipe.
Fig. 4.1.4q LKH Prime Fig. 4.1.4r LKH Prime (US version)
68
4.0
Pump
Description

1. Liquid ring is formed due
to rotations of airscrew
2. Recirculation pipe
3. Water seal is created
4. Liquid/air mix passes
through the canister
5. Liquid is transferred
LKH Prime, Principle of Operation
Its principal of operation is that as the Alfa Laval LKH
Prime pump starts up, the centrifugal force generated
from the rotation of the airscrew and the initial priming
liquid causes the formation of a liquid ring in the pump
head canister (1). This also fills the recirculation pipe (2),
thereby achieving the initial prime (Fig. 4.1.4s).
By design, the canister is offset from the centre of the
airscrew and the resultant liquid ring creates a water
seal between the airscrew hub and the top of the
canister (3).
Due to the offset design, an air column is created
between the airscrew hub and the liquid ring at the
bottom of the canister (1). The rotating vanes of the
airscrew separate the air column into air pockets,
which are forced through the canister into the impel-
ler’s suction stage.
Some of the initial priming liquid recirculates from the
casing discharge into the airscrew casing through the
recirculation pipe (2). Until all the air has been evacuat-
ed, air pockets will continue to be generated.
When the air content is just a few percent, the air is
contained as bubbles in the liquid. No air pockets are
generated. Instead the liquid/air mix passes through
the canister into the impeller’s suction stage (4). Here,
the pump acts as a traditional centrifugal pump, trans-
ferring the liquid through the discharge (5) at a higher
velocity and pressure.
When there is no air present, the canister and recircu-
lation loop have no function and are completely filled
with liquid. The liquid passes through the canister into
the impeller’s suction stage. Here again, the pump
acts as a traditional centrifugal pump, transferring the
liquid through the discharge at a higher velocity and
pressure.
The LKH Prime range is available in three sizes, LKH
Prime-10, -20 and -40
/hr (1233 US gal/
Fig. 4.1.4s Alfa Laval LKH Prime Pump
5
4
3 2
1
69
4.0
Pump
Description

LKH Prime UltraPure Range
The Alfa Laval LKH Prime UltraPure is designed
to meet the stringent demands and regulations of
high-purity applications across the biotechnology
and pharmaceutical industries. Where material
integrity, high efficiency, exceptional cleanability,
contamination safety, robust design and low
maintenance are of paramount importance
(Fig. 4.1.4t - 4.1.4u).
It is ideal for tank emptying and CIP return applica-
tions; having verified and effective CIP cleanability.
The LKH Prime UltraPure can also be used as a
product pump.
requirements.
There are two sizes available, being LKH Prime-
UltraPure 10 and 20.
/hr (308 US gal/min) and differ-
ential pressures up to 4 bar (58 PSIG) for 50 Hz, and
80 m3
/hr (350 US gal/min) up to 5.5 bar (80 PSIG) for
60 Hz.
Fig. 4.1.4t LKH Prime -UltraPure Fig. 4.1.4u LKH Prime-UltraPure (US version)
70
4.0
Pump
Description

4.2 Rotary Lobe Pumps
4.2.1 General
The Alfa Laval range of Rotary Lobe Pumps with its
non-contact pump element design has the ability to
cover a wide range of applications in industry. The
hygienic design, anti-corrosive stainless steel con-
struction and smooth pumping action have long
established these pumps in the food, beverage, dairy,
personal/homecare, and pharmaceutical industries.
Attributes include:
• Gentle transfer of delicate suspended solids
• Bi-directional operation
• Compact size with high performance and low
energy input
• Ability to pump shear sensitive media
Alfa Laval ranges of Rotary Lobe pumps are of con-
ventional design operating with no internal contacting
parts in the pump head. The pumping principle is
explained with reference to the diagram below, which
shows the displacement of fluid from pump inlet to
outlet. The rotors are driven by a gear train in the pump
gear gearbox providing accurate synchronisation or
timing of the rotors. The rotors contra-rotate within the
pump head carrying fluid through the pump, in the
cavities formed between the dwell of the rotor and the
interior of the rotor case.
In hydraulic terms, the motion of the counter rotating
rotors creates a partial vacuum that allows atmos-
pheric pressure or other external pressures to force
fluid into the pump chamber. As the rotors rotate an
expanding cavity is formed which is filled with fluid.
As the rotors separate, each dwell forms a cavity. The
meshing of the rotor causes a diminishing cavity with
the fluid being displaced into the outlet port.
Horizontally ported pump (top shaft drive)
1 2 3 4
1 2 3 4
Vertically ported pump (left hand shaft drive)
71
4.0
Pump
Description

4.2.3 Pump Range
Alfa Laval Rotary Lobe Pumps can be supplied bare
shaft (without drive) or complete with geared electric
motor (see section 8.2.7). Ranges primarily as follows:
SRU Range
The SRU pump range has been designed for use on
general transfer duties throughout the beverage, dairy,
food, home/personal care, and chemical manufactur-
ing processes.
The SRU range is available in six gearbox sizes each
having two pump head displacements and mostly two
different shaft materials (Table 4.2.3a).
• Displacement is the theoretical amount of fluid the
pump will transfer per revolution
• Duplex stainless steel shaft material used for higher
pressures
The SRU pump range incorporates a universally
mounted gearbox which gives the flexibility of
mounting pumps with the inlet and outlet ports
in either a vertical or horizontal plane by changing
the foot and foot position. This pump range also
incorporates full bore through porting complying
with international standards BS4825/ISO2037,
maximising inlet and outlet port efficiency and
NPSH characteristics.
pressures up to 20 bar (290 PSIG).
The SRU range dependent upon seal configuration
conforms to US 3A requirements.
Frame
Size
Model
Port
Position
Shaft
Material
Displacement Max. Pressure (S or D) Max.
speed
(rpm)
litres/
100 rev
US gal/
100 rev
bar PSI
1
SRU1/005 L or H D 5.3 1.40 8 115 1000
SRU1/008 L or H D 8.5 2.25 5 75 1000
2
SRU2/013 L or H S or D 12.8 3.38 10/15 145/215 1000
SRU2/018 L or H S or D 18.1 4.78 7/10 100/145 1000
3
SRU3/027 L or H S or D 26.6 7.03 10/15 145/215 1000
SRU3/038 L or H S or D 38.4 10.2 7/10 100/145 1000
4
SRU4/055 L or H S or D 55.4 14.6 10/20 145/290 1000
SRU4/079 L or H S or D 79.0 20.9 7/15 145/215 1000
5
SRU5/116 L or H S or D 116 30.7 10/20 145/290 600
SRU5/168 L or H S or D 168 44.4 7/15 145/215 600
6
SRU6/260 L or H S or D 260 68.7 10/20 145/290 500
SRU6/353 L or H S or D 353 93.2 7/15 145/215 500
L - Horizontal Porting
H - Vertical Porting
S - Stainless Steel
D - Duplex Stainless Steel
Nomenclature example: SRU4/079/HD is the SRU4/079 with vertical ports and 15 bar (215 PSI) max. pressure.
Pump Nomenclature
Table 4.2.3a
Fig. 4.2.3a SRU
72
4.0
Pump
Description

Frame Size Model
Displacement Max. Pressure (S or D)
Max. speed
(rpm)
litres/100 rev
US gal/100
rev
bar PSI
1
SX1/005 5 1.32 12 175 1400
SX1/007 7 1.85 7 100 1400
2
SX2/013 13 3.38 15 215 1000
SX2/018 18 4.78 7 100 1000
3
SX3/027 26 7.03 15 215 1000
SX3/035 35 9.25 7 100 1000
4
SX4/046 46 12.2 15 215 1000
SX4/063 63 16.7 10 145 1000
5
SX5/082 82 21.7 15 215 600
SX5/115 115 30.4 10 145 600
6
SX6/140 140 37 15 215 500
SX6/190 190 50.2 10 145 500
7
SX7/250 250 66.1 15 215 500
SX7/380 380 100 10 145 500
Pump Nomenclature
Table 4.2.3b
SX Range
The SX pump range is designed for gentle transpor-
tation of process fluids in hygienic and ultra-clean
applications (Fig. 4.2.3b). Suited for use in the home
and personal care sector, and for demanding food and
dairy applications. This pump range like the SRU range
incorporates a universally mounted gearbox which
gives the flexibility of mounting pumps with the inlet
and outlet ports in either a vertical or horizontal plane
by changing the foot and foot position. This pump
range also incorporates full bore through porting com-
plying with international standards BS4825/ISO2037,
maximising the inlet and outlet efficiency of the pump
and the NPSH characteristics.
The SX range has been certified by EHEDG (European
Hygienic Equipment Design Group) as fully CIP
cleanable to their protocol. In addition to being EHEDG
compliant, the SX pump also conforms to the US 3A
standard and all media contacting components are
FDA compliant. All media contacting elastomers are
controlled compression joints to prevent pumped me-
dia leaking to atmosphere (see section 6.2).
The SX range is available with seven gearboxes each
having two pump head displacements. Flow rates up
to 115 m3
/hr (506 US gal/min) and pressures up to 15
bar (215 PSIG) (Table 4.2.3b).
Fig. 4.2.3b SX
73
4.0
Pump
Description

SX UltraPure Range
The SX UltraPure pump range is designed for gentle
transportation of process fluids in hygienic and high
purity applications (Fig. 4.2.3c). Suited for use in the
pharmaceutical, biotechnology and personal care
sector.
This pump range also incorporates full bore through
porting complying with international standards
BS4825/ISO2037, maximising the inlet and outlet
efficiency of the pump and the NPSH characteristics.
The SX UltraPure range has been certified by EHEDG
(European Hygienic Equipment Design Group) as fully
CIP cleanable to their protocol. In addition to being
Frame Size Model
Displacement Max. Pressure
Max. speed (rpm)
litres/100 rev US gal/100 rev bar PSI
1
SX UltraPure 1/005 5 1.32 12 175 1400
SX UltraPure 1/007 7 1.85 7 100 1400
2
SX UltraPure 2/013 13 3.38 15 215 1000
SX UltraPure 2/018 18 4.78 7 100 1000
3
SX UltraPure 3/027 26 7.03 15 215 1000
SX UltraPure 3/035 35 9.25 7 100 1000
4
SX UltraPure 4/046 46 12.2 15 215 1000
SX UltraPure 4/063 63 16.7 10 145 1000
5
SX UltraPure 5/082 82 21.7 15 215 600
SX UltraPure 5/115 115 30.4 10 145 600
6
SX UltraPure 6/140 140 37 15 215 500
SX UltraPure 6/190 190 50.2 10 145 500
7
SX UltraPure 7/250 250 66.1 15 215 500
SX UltraPure 7/380 380 100 10 145 500
Pump Nomenclature
Table 4.2.3c
EHEDG compliant all media contacting components
are FDA compliant with USP Class VI elastomers.
All media contacting elastomers are controlled
compression joints to prevent pumped media
leaking to atmosphere (see section 6.2).
requirements.
The SX UltraPure range is available with seven gear-
boxes each having two pump head displacements
(Table 4.2.3c).
pressures up to 15 bar (215 PSIG).
Fig. 4.2.3c SX UltraPure
74
4.0
Pump
Description

Frame Size Model
Displacement Max. Pressure (S or D) Max. speed
(rpm)
10
OptiLobe 12 6 1.48 8 115 1000
OptiLobe 13 10 2.61 8 115 1000
20
OptiLobe 22 17 4.49 8 115 1000
OptiLobe 23 21 5.55 8 115 1000
30
OptiLobe 32 32 8.45 8 115 1000
OptiLobe 33 40 10.57 8 115 1000
40
OptiLobe 42 64 16.91 8 115 1000
OptiLobe 43 82 21.66 8 115 1000
50
OptiLobe 52 117 30.89 8 115 750
OptiLobe 53 172 45.41 8 115 750
Pump Nomenclature
Table 4.2.3d
OptiLobe Range
The Alfa Laval OptiLobe Rotary Lobe Pump is a
cost-effective alternative for general applications that
require gentle product treatment and easy servicea-
bility (Fig. 4.2.3d). Suited for use in applications across
the dairy, food, beverage, home, and personal care in-
dustries. Easy to adapt to vertical or horizontal porting
by changing the foot position on the gearbox provides
good flexibility for a variety of installations.
The OptiLobe range has been certified by EHEDG
EHEDG compliant, the OptiLobe pump also conforms
to the US 3A standard and all media contacting com-
ponents are FDA compliant.
The OptiLobe range is available with five gearboxes
each having two pump head displacements. Flow
rates up to 77 m3
/hr (339 US gal/min) and pressures
up to 8 bar (115 PSIG) (Table 4.2.3d).
Fig. 4.2.3d OptiLobe
75
4.0
Pump
Description

4.3.1 General
The Alfa Laval range of Circumferential Piston Pumps
are designed for hygienic applications within the dairy,
food, beverage, home, and personal care industries.
The highly efficient design with close clearances and
long slip paths is particularly suited to applications that
are low in viscosity with medium to high discharge
pressures and require equipment that can be cleaned
in place (CIP).
Attributes include:
• Excellent suction performance
• Higher pressure capabilities
• Bi-directional operation
4.3 Circumferential Piston Pumps
The Alfa Laval Circumferential Piston pumping principle
is explained with reference to the diagram above (Fig.
4.3.1a), which shows the displacement of fluid from
pump inlet to outlet. The rotors are driven by a gear
train in the pump gear gearbox providing accurate
synchronisation or timing of the rotors. The rotors
contra-rotate within the pump head carrying fluid
through the pump, in a channel between the rotor
wings and the dwell of the rotors and the interior of
the rotor case.
The rotor pistons with close running clearances rotate
around the circumference of the channel in the pump
casing. This continuously generates a partial vacuum
at the suction port as the rotors un-mesh, causing fluid
to enter the pump. The fluid is transported around the
channel by the rotor pistons and is displaced into the
outlet port as the rotor pistons re-mesh. The direction
of flow is reversible.
Suction Discharge
76
4.0
Pump
Description

DuraCirc Range
Designed for Cleaning-in-Place (CIP), the Alfa Laval
DuraCirc is ideal for hygienic applications within the
dairy, food, beverage, home and personal care
industries (Fig. 4.3.1b). The highly efficient design
is particularly suited to applications that are low in
viscosity with medium to high discharge pressures
and require equipment that can be cleaned in place.
DuraCirc has a variety of options available to suit may
different processes and is designed to keep processes
running with minimal maintenance requirements.
The DuraCirc range has been certified by EHEDG
EHEDG compliant, the DuraCirc pump also conforms
to the US 3A standard, and all media contacting
components are FDA compliant. All media contact-
ing elastomers are controlled compression joints to
prevent pumped media leaking to atmosphere (see
section 6.2).
The DuraCirc range is available with five gearboxes
and a total of thirteen pump head volumetric displace-
ments. Flow rates up to 149 m3
and pressures up to 40 bar (580 PSIG) (Table 4.3.3a).
Frame Size Model
Displacement Max. Pressure Max. speed
(rpm)
30
DuraCirc 32 3 0.79 25 362 1000
DuraCirc 33 6 1.58 25 362 1000
DuraCirc 34 12 3.17 16 232 1000
40
DuraCirc 42 23 6.07 20 290 750
DuraCirc 43 29 7.66 13 188 750
50
DuraCirc 52 38 10.03 37 536 750
DuraCirc 53 59 15.57 25 362 750
DuraCirc 54 96 25.3 16 232 750
60
DuraCirc 62 144 38.04 37 536 600
DuraCirc 63 197 52.03 25 362 600
70
DuraCirc 72 192 50.7 40 580 500
DuraCirc 73 286 75.55 25 362 500
DuraCirc 74 414 109.4 16 232 500
Pump Nomenclature
Table 4.3.3a
Fig. 4.3.1b DuraCirc
77
4.0
Pump
Description

Frame Size Model
Displacement Max. Pressure (S or D) Max. speed
(rpm)
40 DuraCirc Aseptic 42 23 6.07 20 290 750
50
DuraCirc Aseptic 53 59 15.57 25 362 750
DuraCirc Aseptic 54 96 25.3 16 232 750
Pump Nomenclature
Table 4.3.3b
DuraCirc Aseptic Range
Designed for sterile flushing at all product media to
atmosphere interfaces, as well as Cleaning-in-Place
(CIP), the Alfa Laval DuraCirc Aseptic is ideal for
aseptic processing within the dairy, food, beverage,
home, and personal care industries. The highly
efficient design is particularly suited to applications
that are low in viscosity with medium to high discharge
pressures and require equipment that can be cleaned
in place (Fig. 4.3.1c).
As with DuraCirc pump the Alfa Laval DuraCirc Aseptic
is certified with EHEDG and also conforms to the US
3A standard and all media contacting components are
FDA compliant.
The DuraCirc Aseptic Circumferential Piston Pump is
available with five different pump head displacements
to handle flow rates up to 103 m3
and differential pressures up to 25 bar (362 PSIG)
(Table 4.3.3b).
Fig. 4.3.1c DuraCirc Aseptic
78
4.0
Pump
Description

4.4 Twin Screw Pumps
4.4.1 General
The Alfa Laval Twin Screw Pump with non-contacting
pump head, designed for handling sensitive, abrasive,
and high and low viscosity fluids has the ability to
cover a wide range of applications, providing process
flexibility. It’s hygienic design with smooth, low pulsa-
tion characteristics provide excellent solids handling
capabilities reducing the risk of product damage. The
ability to operate these pumps across a wide speed
range makes it capable of handling both product
transfer duties and Cleaning-in-Place (CIP) and is
widely used in the dairy, food, beverage, home, and
personal care industries.
Attributes include:
• Greater process flexibility
• Superior suction performance
• Low pulsation flow
• Ease of service
The Alfa Laval Twin Screw Pump is a rotating positive
displacement pump which uses two intermeshed
screws to convey product in the horizontal axis (Fig.
4.4.1a). As the pump rotates, the intermeshing of
the two contra rotating screws along with the pump
housing form volumetric chambers. These chambers
fill with the pumped fluid and move it axially from the
suction side, gradually building up the pressure across
the chambers to the higher-pressure discharge side of
the pump.
Typically driven via a direct drive motor using a fre-
quency inverter for speed variation provides the flexibil-
ity on adapting the speed to meet each duty condition
including cleaning in place (CIP) fluids.
Fig. 4.4.1a Twin Screw axial flow transfer
79
4.0
Pump
Description

OS Twin Screw Range
The Alfa Laval OS Twin Screw Pump is designed for
handling sensitive, abrasive and high and low viscosity
fluids, the Alfa Laval Twin Screw Pump is ideal for use
in hygienic applications across the dairy, food, bev-
erage, and home and personal care industries. Quiet
and virtually pulse-free, the pump provides smooth
and gentle operation, making it an excellent choice
for handling sensitive products. Two-in-one operation
provides easy handling of process media of varying
viscosities as well as CIP fluids (Fig. 4.4.1b).
The OS Twin Screw features a clean, external stain-
less-steel finish with profiled elastomers and mechani-
cal seals fully surrounded by the product. Designed for
maximum cleanability using FDA-conforming materials,
the pump is both EHEDG- and 3-A certified.
The OS Twin Screw is available in sixteen models
based on four frame sizes. The OS10 and OS40
frames have three different screw profiles for varying
pressure, flow and solids-handling capabilities, whilst
the OS20 & OS30 frames have five different screw
profiles. This provides a wide range of performance to
enable the user to select the optimal pump for each
application. Flow rates up to 150 m3
/hr (660 US gal/
min) and differential pressures up to 16 bar (232 PSIG).
Fig. 4.4.1b OS Twin Screw
80
4.0
Pump
Description

81
4.0
Pump
Description

This chapter describes the materials, both
metallic and elastomeric, used in the con-
struction of the Alfa Laval pump portfolio.
5.1 Main Components
Pumps can be manufactured from several varied
materials, dependent upon the product being pumped
and its environment.
For Alfa Laval, the pump ranges can be split into two
main construction categories:
• Product Wetted Parts
(i.e., metallic, and elastomeric parts in contact with
the fluid being pumped)
• Non-product Wetted Parts
(i.e., metallic, and elastomeric parts not in contact
with the fluid being pumped)
82
5.0
Pump
Materials
of
Construction

Pump Materials
of Construction
5.0
83
5.0
Pump
Materials
of
Construction

Centrifugal Pumps - LKH ranges
Main Pump Component Product Wetted Parts Non-product Wetted Parts
Adaptor AISI 304 or Werkstoff 1.4301
Backplate AISI 316L or Werkstoff 1.4404
Impeller AISI 316L or Werkstoff 1.4404
Pump Casing AISI 316L or Werkstoff 1.4404
Pump Shaft AISI 316L or Werkstoff 1.4404
Shroud and Legs AISI 304 or Werkstoff 1.4301
Table 5.1a
Centrifugal Pumps - SolidC + SolidC UP ranges
Adaptor AISI 304 or Werkstoff 1.4301
Shroud AISI 304 or Werkstoff 1.4301
Legs Special - Plastic Coated
Table 5.1b
Fig. 5.1a LKH Centrifugal pump
1
2
3
1. Casing
2. Adaptor
3. Shroud
1. Casing
2. Shroud
3. Legs
Fig. 5.1b SolidC Centrifugal pump
1
2
3
84
5.0
Pump
Materials
of
Construction

Centrifugal Pumps - ICP2000 range (authorised channels only)
Adaptor Painted Zinc Coated Cast Steel
Shroud AISI 304 or Werkstoff 1.4301
Legs Special - Plastic Coated
Table 5.1c
Fig. 5.1c ICP2000 Centrifugal pump
3
1
2
1. Casing
2. Adaptor
3. Backplate
85
5.0
Pump
Materials
of
Construction

Rotary lobe pumps - SRU + SX ranges
Main Pump
Component
SRU Models SX + SX UP Models
Metallic
Product Parts
Metallic Non-product
Wetted Parts
Metallic Product
Wetted Parts
Metallic Non-product
Wetted Parts
Gear Case AISI 304 or Werkstoff
1.4301
AISI 304 or Werkstoff
1.4301
Rotor Werkstoff 1.4404 or AISI
316L/Non-Galling Alloy
ASTM A-494
Werkstoff 1.4404 or AISI
316L
Rotor Case EN 1.4409 (CF-3) or AISI
316C12/Werkstoff 1.4404
or AISI 316L
EN 1.4409 or 316C12/
316L
Rotor Case
Cover
316L
316L
Shaft Werkstoff 1.4404 or 316L
Duplex stainless steel
(AISI 329 or grade 1.4462)
Duplex stainless steel
Table 5.1d
Fig. 5.1d SRU Rotary lobe pump
2
4
1
6
5
3
1. Product seal area
2. Rotor case
3. Rotor case cover
4. Ports
5. Gearbox
6. Drive shaft
86
5.0
Pump
Materials
of
Construction

Circumferential piston pumps - DuraCirc + DuraCirc Aseptic
Main Pump Component Metallic Product Wetted Parts Metallic Non-product Wetted Parts
Gear Case AISI 304 or Werkstoff 1.4301
Rotor Non-Galling Alloy/ASTM A-494
Rotor Case Werkstoff 1.4404 or AISI 316L/EN
1.4409 (CF-3) or AISI 316C12
Rotor Case Cover Werkstoff 1.4404 or AISI 316L
Shaft Duplex stainless steel
Table 5.1d
Twin screw pumps - OS
Main Pump Component Metallic Product Wetted Parts Metallic Non-product Wetted Parts
Gear Case EN 1.4408 (CF-8) or 316 C16
Screws Werkstoff 1.4404 or AISI 316L
Optional: Diffusion hardened
- 1092 HV0.05
Casing Werkstoff 1.4404 or AISI 316L
Diffusion hardened - 1092 HV0.05
Case Cover Werkstoff 1.4404 or AISI 316L
Shafts Werkstoff 1.4404 or AISI 316L
Table 5.1e
Fig. 5.1d Circumferential piston pump
1
2
3
4
Fig. 5.1e Twin Screw pump
4 2
3
1
2. Gearbox
3. Ports
4. Rotor case cover
2. Gearbox
3. Ports
4. Rotor Case
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5.2 Stainless Steel
Hygienic demands have led stainless steel to be
accepted as the top material choice within the food,
beverage & pharmaceutical processing/services for
product equipment.
This equipment must possess product integrity (no
corrosion or leaks), cleanliness, ease of cleaning and
ease of inspection. The equipment must also be able
to resist chemical solutions used in cleaning, such as
chloride-based sterilising agents, acids, and alkalis.
Stainless steel meets all these requirements for pump
designs with the most commonly grades within
hygienic applications being austenitic types; SS
(Stainless Steel) 304 (1.4301), 316 (1.4401) and 316L
(1.4404) (Table 5.2a).
Differences between SS 304 and SS 316:
• Both 304 and 316 are easily welded and formed
• Both types are non-magnetic
• 304 contains 18% chromium 8% nickel
316 contains 17% chromium
• 304 contains no trace of molybdenum
316 contains 2.1% molybdenum
Stainless
Steel Name
Composition Characteristics Application areas
Alloy 304 Also known as 18/8 for its com-
position of 18% chromium and
8% nickel
Excellent in a wide range of
atmospheric environments and
many corrosive media. Subject
to pitting and crevice corrosion
in warm chloride environments,
and to stress corrosion cracking
approximately above 60° C
Non to low chloride containing
water applications, nitric acid,
and oleum
Alloy 316 A composition of 18% chromi-
um and 10% nickel and 2% of
molybdenum
The 316 grade is used instead
of 304 in cases where higher
resistance to pitting and crevice
corrosion is required, in chloride
environments
Versatile material that is used in
a very wide range of applications
like; food, dairy, beverage, organ-
ic acids and pharmaceutical, to
mention a few
Table 5.2a Stainless Steel Alloys
The biggest difference between the grades is molyb-
denum is added to SS 316 to increase corrosion and
pitting resistance.
SS 316L is almost identical to SS 316. The only
difference is the lower carbon content with SS 316
having maximum value of 0.08% and SS 316L having
maximum value of 0.03%.
Duplex Steel
Certain applications within targeted industries pose
challenges that cannot be met by austenitic stainless
steel alone.
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Duplex stainless steels (AISI 329) are extremely corro-
sion resistant alloys. Their microstructures consist of
a mixture of austenite and ferrite phases. As a result,
duplex stainless steels display properties characteristic
of both austenitic and ferritic stainless steels.
Strengths of duplex stainless steels can in some cases
be double that for austenitic stainless steels, making
it an ideal choice of alloy for the construction of pump
shafts to handle higher pressure applications.
Whilst duplex stainless steels are considered resistant
to stress corrosion cracking, they are not as resistant
as ferritic stainless steels. However, the corrosion re-
sistance of the least resistant duplex stainless steels is
greater than that for the most used grades of stainless
steels, i.e., 304 and 316.
Duplex stainless steels have good weldability. All
standard welding processes can be used. They are
not as easily welded as the austenitic grades, but low
thermal expansion in duplex grades reduces distortion
and residual stresses after welding.
Duplex steels are also magnetic, a property that can
be used to easily differentiate them from common
austenitic grades of stainless steel.
Please contact Alfa Laval on the possibility of providing
a hygienic pump manufactured of Duplex steel or other
exotic alloys suited for your requirements.
For description of elastomers used see section 5.3.
For mechanical seal components see section 6.1.
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5.3 Stainless Steel Surfaces
The ‘standard’ machined surface finish on pumps can
be enhanced by the following methods:
• Rumbling
• Shot blasting
• Electropolishing
• Mechanical (Hand) polishing
Rumbling
This is achieved by vibrating the pump components
with abrasive particulate such as stones and steel
balls.
Shotblasting
This method involves blasting finished components
with small metallic particles at great force to achieve
the surface finish required. For Alfa Laval centrifu-
gal, stainless steel pump components, fine particles
of stainless steel are used in this process to avoid
contamination.
Surface finish of product wetted steel components
is a major factor in the food, pharmaceutical and
biotechnology industries where hygiene and cleanability
are of paramount importance.
For Alfa Laval Centrifugal Pumps see table below:
Pump surfaces Standard surface roughness
Ra (mm) by Rumbling method
Optional surface roughness (3A
finish) Ra (mm) by Mechanical
(Hand) method
Optional surface roughness (3A fin-
ish) Ra (mm) by shot blasting (Hand
or Electropolished)
Product wetted
surfaces
< 1.6 (64 Ra) < 0.8 (32 Ra) < 0.5 (20 Ra)
External exposed
surfaces
< 1.6 (64 Ra) < 1.6 (64 Ra) < 1.6 (64 Ra)
Cast surfaces < 3.2 (125 Ra) } 3.2 (125 Ra) } 3.2 (125 Ra)
Other surfaces } 6.3 (250 Ra) } 6.3 (250 Ra) } 6.3 (250 Ra)
Table 5.3a
Electropolishing
This is an electro-chemical process in which the stain-
less steel component is immersed into a chemical bath
and subjected to an electrical current. A controlled
amount of metal is removed from all surfaces evenly.
The appearance is ‘Semi bright.’
Mechanical (Hand)
This is required when it is necessary to reach a certain
Ra surface finish for customers beyond that achieved
by electropolishing only i.e., a ‘Mirror finish’.
It typically involves:
• Fine grinding using felt and compound
• Brushing using bristle brushes and compound to
remove any cutting marks left from fine grinding,
and to reach any awkward areas
• Polishing using mops and compound to obtain a
mirror polished effect
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Surface Roughness
The most used surface roughness measurement is Ra
and is defined as ‘the arithmetic mean of the absolute
value of the departure of the profile from the mean
line’ (Fig. 5.3a). Ra is measured in micron (µm). The
surface roughness can alternatively be specified by a
Grit value. The Grit value specifies the grain size of the
coating of the grinding tool used.
The approximate connection between the Ra value
and the Grit value is as follows:
Ra = 0.8 µm (32 Ra) ≈ 150 Grit (3A standard)
Ra = 1.6 µm (64 Ra) ≈ 100 Grit
Alfa Laval Centrifugal pumps supplied in the US have
all product wetted surfaces and external exposed
surfaces to 0.8 Ra.
For Alfa Laval Rotary Lobe Pumps the surface rough-
ness on product wetted parts such as rotors, rotor
case, rotor nuts and rotor case covers is as follows:
‘Standard’ 0.8 Ra
Electropolishing 0.8 Ra
Mechanical (Hand) 0.38 Ra
Passivation
The passivation of stainless steel is a process per-
formed to make a surface passive, i.e., a surface film
is created that causes the surface to lose its chemical
reactivity.
Stainless steel passivation unipotentialises the
stainless steel with the oxygen absorbed by the
metal surface, creating a monomolecular oxide film.
This process returns the stainless steel back to its
original specifications. When a part is machined,
various particles can permeate the surface of the
base metal, weakening its resistance to corrosion and
making the part more susceptible to environmental
factors. Debris, dirt and other particles and residue
such as free iron, grease, and machining oils all affect
the strength of the natural surface and can become
embedded in the surface during the machining pro-
cess. These often go unseen to the human eye and
are often the cause of the deterioration. The passiva-
tion process improves and purifies the surface of the
part. The restored surface acts as a protective coating
to environmental factors such as air, water, and other
extreme environments.
It is important to mention that passivation does not
change the outward appearance of the base metal.
Advantages of Passivation
• Improved corrosion resistance
• Uniform, smooth appearance & finish
• Cleanliness
• Improved & extended life of product
Note: Passivation is also accomplished by
electropolishing.
Fig. 5.3a Surface roughness
Real surface
+y
L
R
a
0
-y Mean line
X
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Materials
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5.4 Elastomers
Alfa Laval pump ranges incorporate elastomers of
different material and characteristics dependent
upon application within the pump and the fluid being
pumped.
Various elastomer types are specified below. It is
difficult to predict the lifetime of elastomers as they
will be affected by many factors, e.g., chemical attack,
temperature, mechanical wear etc.
It is important to note all Alfa Laval pumps are sup-
plied with FDA, 3A EC1935/2004 and EC2023/2006
conforming elastomer grades as standard.
A selection guide is shown in section 14.10.
EPDM (Ethylene Propylene)
This is a gasket material with excellent heat resistance.
It is resistant to oxidization, acids, bases, and tough
CIP (Cleaning-in-Place).
• Used as static or dynamic seals
• Resistant to most products used within the food
industry
• Resistant to ozone and radiation
• Temperature range - min. -40° C to max. +150° C
(min. -40° F to max. +302° F)
• Not resistant to organic & non-organic oils/greases
and aliphatic, aromatic, chlorinated hydrocarbons
FPM/FKM (Fluorinated rubber)
Alternatively known as Viton®
. FPM is a fluoro rubber
that has excellent chemical resistance to a very wide
array of substances. It has excellent resistance to oils
including aromatics, acids, oxidization, and heat.
• Often used when other rubber qualities are
unsuitable
• Resistant to most chemicals and ozone
(min. -4° F to max. +392° F)
• Not suitable for fluids such as steam, lye, acid,
and high temperature alcohol
FFPM/FFKM (Perfluoroelastomer)
Perfluoroelastomers contain an even higher amount of
fluorine than FKM and is typically used in applications
where compatibility is limited to standard offerings.
• Resistant to ozone and almost all products
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(min. -4° F to max. +500° F)
• More elastic than PTFE (Polytetrafluoro Ethylene)
• Not suitable with molten alkali metals
PTFE (Polytetrafluoro Ethylene)
Polytetrafluoroethylene is a synthetic fluoropolymer
of tetrafluoroethylene that has numerous applica-
tion uses. It is also known by common trade name
TEFLON™.
• Used as static seals
• Resistant to ozone and almost all products
(min. -22° F to max. +392° F)
• Not elastic, tendency to compression set
MVQ (Silicone)
MVQ is a silicone rubber with suitable properties for
both high and low temperatures. Due to hydrolysis
(cleavage of chemical bonds by the addition of water)
its resistance is limited to acids, bases, and steam
• Resistant to ozone, alcohol, glycols, and most
products used within food industry
(min. -58° F to max. +446° F)
• Not resistant to steam, inorganic acids, mineral
oils, or most organic solvents
FEP (Fluorinated Ethylene Propylene)
• FEP covered (vulcanised) FPM or MVQ O-rings
• Resistant to ozone
• Resistant to almost all products
• Suitable for temperatures up to approx. 200° C
(392° F)
• More elastic than PTFE
Alternative options upon request
Kalrez®
/Chemraz®
(Perfluoroelastomer)
Like FFPM, these Perfluoros are trademarked and
have numerous material grades that can cover all con-
ceivable application requirements.
• Resistant to ozone
• Resistant to almost all products
• Temperature range – min. -40° C to max. +365° C
(min. -40° F to max. +689° F) dependent on grade
• Elastic
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This chapter describes the principle of pump
sealing and illustrates the different sealing
arrangements used on Alfa Laval pump ranges.
A general seal selection guide is included,
along with various operating parameters.
This chapter covers the primary shaft sealing devices
used on Alfa Laval Centrifugal, Rotary Lobe, Internal
Gear, Circumferential Piston and Twin Screw pumps.
Other proprietary seals not detailed in this chapter,
such as O-rings and lip seals can be found on the
pump head and gear case.
“A Pump is only as good as its shaft seal”
A successful pump application largely depends upon
the selection and application of suitable fluid sealing
devices. Just as we know that there is no single pump
that can embrace the diverse range of fluids and
applications whilst meeting individual market require-
ments and legislations, the same can be said of fluid
sealing devices. This is clearly illustrated by the large
range of shaft seal arrangements, such as mechani-
cal, lip or O-ring seals, that are available to the pump
manufacturer.
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Pump Sealing
6.0
95
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Pump
Sealing

Shaft sealing devices used in the various pump
technologies in the Alfa Laval pump portfolio include:
Mechanical Seals
• Single externally mounted
• Single internally mounted
• Single externally mounted for external flush
• Single internally mounted for product recirculation
or external flush
• Double ‘back-to-back’ with the inboard seal
externally mounted for flush
O-ring seals
• Single
• Single with flush
Centrifugal pumps only have one shaft seal whereas
Rotary Lobe, Internal Gear, Circumferential Piston
and Twin Screw pumps employ a minimum of two
shaft seals (one per shaft). Generally, all shaft seals
are under pressure with the pressure gradient across
the seal being from pumped fluid to atmosphere. The
exception to this is with a double seal, where the flush
pressure can be greater than the differential pressure
in the pump chamber. This results in the pressure
gradient being reversed.
Mechanical seals meet the majority of application
demands and of these, single and single flushed
seals are most frequently specified. The application
of double mechanical seals is increasing to meet both
process demands for higher hygienic standards and
legislation requirements, particularly those related to
emissions.
The majority of proprietary mechanical seals available
from seal manufacturers have been designed for single
shaft pump concepts, for example Centrifugal pumps.
Such pump types do not impose any radial or axial
constraints on seal design. However, on Rotary Lobe,
Circumferential Piston and Twin Screw pumps the
need to minimise the shaft extension beyond the front
bearing places significant axial constraints. If this were
extended, the shaft diameter would increase introduc-
ing a radial constraint - because shafts on the above
referenced pump technologies are in the same plane,
the maximum diameter of the seal must be less than
the shaft centres. Most designs therefore can only
accommodate ‘bespoke’ or ‘customised’ seal design.
This is not done to take any commercial advantage,
rather it is as a consequence of these pumps design
concept.
There is often more than one solution and
sometimes no ideal solution, therefore a
compromise may have to be considered.
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Selection of shaft seals is influenced by many variables:
• Shaft diameter and speed
• Fluid to be pumped
Temperature - effect on materials?
- can interface film be maintained?
Viscosity - drag on seal faces?
- clogging of seal restricting movement?
- can interface film be established and maintained?
- stiction at seal faces?
Fluid behaviour - does product shear, thin, thicken
or ‘work’ - balling/carbonise?
Solids - size?
- abrasiveness?
- density?
- clogging of seal restricting movement?
Thermal stability - what, if any change?
Air reacting - what, if any change?
• Pressure - within seal limits?
- fluctuations?
- peaks/spikes?
- cavitation?
• Services - flush?
- pressure?
- temperature?
- continuity?
• Health and safety - toxic?
- flammable?
- explosive?
- corrosive?
- irritant?
- carcinogenic?
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The Secondary Seal
This is required to provide a seal between the primary
seal rings and the components with which they inter-
face. Also, it can provide a cushion mounting for the
seat ring to reduce any effects of mechanical stress
i.e., shock loads.
Types of secondary seal are:
• O-rings
• Cups
• Gaskets
• Wedges
For Alfa Laval pump ranges an O-ring or profiled
elastomer is the most commonly type of secondary
seal used. This is a simple and versatile solution and
(dependent on range) is offered in the following com-
prehensive material options:
• NBR
• EPDM
• FPM
• PTFE
• FEP
• FFPM
• Silicone
Note:
USP class VI compliant variants are an available option
on certain ranges, in certain materials.
These are fully described in chapter 11.
6.1 Mechanical Seals
General
Mechanical seals are designed for minimal leakage
and represent the majority of Centrifugal, Rotary Lobe,
Internal Gear, Circumferential Piston and Twin Screw
pump sealing arrangements (Table 6.1a).
Mechanical seal selection must consider:
• The materials of seal construction, particularly
the sealing faces and elastomers
• The mounting attitude to provide the most
favourable environment for the seal
• The geometry within which it is to be mounted
A mechanical seal typically comprises of:
• A primary seal, comprising of stationary and rotary
seal rings
• Two secondary seals, one for each of the station-
ary and rotary seal rings
• A method of preventing the stationary seal ring
from rotating
• A method of keeping the stationary and rotary
seal rings together when they are not hydraulically
loaded i.e., when pump is stopped
• A method of fixing and maintaining the working
length
The Primary Seal
Comprises of two flat faces, one rotating and one sta-
tionary, which support a fluid film, thus minimising heat
generation and subsequent mechanical damage.
Commonly used material combinations are:
Carbon - Stainless Steel
Carbon - Silicon Carbide
Silicon Carbide - Silicon Carbide
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Mechanical Seal Face/’O’ Ring Material Availability
Rotary Seal
Face
Stationary Seal
Face
Elastomer
Pump Type Pump Range
Carbon
Stainless
Steel
Silicon
Carbide
Carbon
Stainless
Steel
Silicon
Carbide
NBR
EPDM
FPM
PTFE
FFPM
Silicone
FEP
Centrifugal LKH/LKH Evap       
LKH Prime      
LKH Multistage      
LKHPF     
LKHI      
LKH UltraPure     
LKH Prime UltraPure     
SolidC       
SolidC UltraPure     
FM       
GM      
Rotary Lobe OptiLobe      
SRU        
SX       
SX UltraPure     
Circumferential Piston DuraCirc      
DuraCirc Aseptic    
Twin Screw OS      
Internal Gear M       
Note 1: LKH Multistage 120 only has EPDM & NBR elastomer option
Note 2: SX1 pump has tungsten carbide seal faces, not silicon carbide seal faces
Table 6.1a
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Rotary Seal Ring Drive
Ideally the selected device listed below will allow for a
degree of axial movement.
• Spring
• Bellows
• Physical positioning
• Elastomer resilience
Stationary Seal Ring Anti-Rotation
Ideally the selected device listed below will also allow
for axial resilience.
• Flats
• Pins
• Elastomer resilience
• Press fit
• Clamps
One of the main causes of seal failure
is for the seal working length not being
correctly maintained.
Working Length
The ideal design should eliminate/minimise possibilities
for error by incorporating (Fig. 6.1a):
• Physical position i.e., step on shaft
• Grub screws
Note:
Some Alfa Laval mechancial seals are self-setting by
design, whereby working length is autoamtically set.
Fig. 6.1a Typical single mechanical seal used in rotary lobe pumps
1 5
7
10 9
2
6
3
11
4 8
Working length
Fig. 6.1b Typical single mechanical seal used in centrifugal pumps
4 3 2 5
9
8 6 7
1
1. Stationary Seal ring
2. Rotary Seal ring
3. Wave Spring
4. Rotary Seal drive ring
5. Stationary Seal drive O-ring
6. Rotary Seal O-ring
7. Rotor
8. Shaft
9. Rotorcase
10. Stationary Seal Ring
Anti-rotation pin
11. Grub screw
2. Rotary Seal ring
3. Spring
4. Drive ring
5. Stationary Seal elastomer
6. Rotary Seal elastomer
7. Impeller
8. Pump shaft
9. Backplate
Process media
Process media
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Sealing

Principle of Mechanical Seal Operation
During pump operation, hydraulic fluid forces combine
with seal design features, including applied spring
force, extremely flat sealing surfaces and seal face
geometry, which push the seal faces together. This
reduces the fluid interface thickness, also called the
interface film, to a minimum, typically 1 µm, as shown
in Fig 6.1c, whilst increasing pressure drop, therefore
minimising pumped fluid leakage.
Mechanical Seal Mounting
Mechanical seals can be mounted externally or
internally.
External Mounted Mechanical Seals
In an externally mounted mechanical seal, the seal is
designed such that the direction of fluid flow across
the seal faces is from the internal to external seal
face diameter, i.e., the fluid is sealing inside to out, as
shown in Fig. 6.1d.
Pumps having externally mounted mechanical seals
include LKH, LKH UltraPure, LKHex, LKH Prime, LKH
Prime UltraPure, Solid C, Solid C UltraPure and SRU.
Fig. 6.1c Principle of mechanical seal operation
Approx. 1µm
Interface film
1
5
6
2
9
Fig. 6.1d Typical external shaft seal
4 3 2 5
9
8 6 7
1
2. Rotary Seal ring
9. Backplate
2. Rotary Seal ring
3. Spring
4. Drive ring
7. Impeller
8. Pump shaft
9. Backplate
Process media
Process media
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Sealing

Internal Mechanical Seals
In an internally mounted mechanical seal, the seal is
designed such that the direction of fluid flow across
the seal faces is from the external to internal seal
face diameter, i.e., the fluid is sealing outside to in, as
shown in Fig 6.1e.
Pumps having internally mounted mechanical seals
include LKHI, LKH Multistage, LKHPF, OptiLobe, SX,
SX UltraPure, DuraCirc, DuraCirc Aseptic and OS Twin
Screw.
In Alfa Laval hygienic pumps, dependent on range,
both the externally and internally mounted types of
mechanical seal are available as single and single
flushed, as well as double versions.
The arrangements are described as follows:
• Single Mechanical Seal
• Single Flushed Mechanical Seal
• Double Flushed Mechanical Seal
Fig. 6.1e Typical internal shaft seal
7
4
9
6
5
8 1 2 3
10 Process media
2. Rotary Seal ring
3. Spring
4. Rotating seal housing
6. Rotary Seal quad ring
7. Impeller
8. Pump shaft
9. Backplate
10. Seal housing quad ring
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Sealing

Single Mechanical Seal
This is the simplest shaft seal version, which has
already been described previously in this chapter.
This seal arrangement is generally used for fluids
that do not solidify or crystallise in contact with the
atmosphere and other non-hazardous duties (Fig. 6.1f).
For satisfactory operation it is imperative the seal is not
subjected to pressures exceeding the maximum
rated pressure of the pump. Also, the pump must
not be allowed to run ‘dry’, thus avoiding damage
to the seal faces, which may cause excessive seal
leakage.
Typical applications are listed below, but full product/
fluid and performance data must be referred to the
seal supplier for verification.
• Alcohol
• Animal Fat
• Aviation Fuel
• Beer
• Dairy Creams
• Fish Oil
• Fruit Juice
• Liquid Egg
• Milk
• Shampoo
• Solvents
• Vegetable Oil
• Water
• Yoghurt
Fig. 6.1f Typical externally mounted single flushed mechanical seal used in rotary
lobe pumps
Seal shown: SRU R90 single flushed seal
8 4 11 3 6
2 10 9
1 5
7
14 12 13 1. Stationary Seal ring
2. Rotary Seal ring
3. Wave Spring
7. Rotor
8. Shaft
9. Rotorcase
Anti-rotation pin
11. Grub screw
12. Lip seal
13. Flush housing
14. Seal abutment spacer
Process media
Flush media
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Single Flushed Mechanical Seal
The definition of ‘flush’ is to provide a liquid barrier or
support to the selected seal arrangement. This seal
arrangement is generally used for any of the following
conditions:
• Where the fluid being pumped can coagulate,
solidify, or crystallise when in contact with the
atmosphere
• When cooling of the seals is necessary dependent
upon the fluid pumping temperature
• In partial vacuum applications, where a barrier to
atmosphere is required
This seal arrangement used on both externally as well
as internally mounted seals requires the supply of
liquid to the atmospheric side of the mechanical seal
to flush the seal area (Fig. 6.1g). The characteristics
of the fluid being pumped, and the duty conditions
will normally determine if a flush is necessary. When
selecting a flushing liquid, you must ensure that it is
chemically compatible with the relevant materials of
pump/seal construction and fully compatible with the
fluid being pumped. Consideration should be given
to any temperature limitations that may apply to the
flushing liquid to ensure that hazards are not created
(i.e., explosion, fire, etc.).
The flushing liquid is usually sealed from external
atmosphere via a lip seal. In Alfa Laval pumps, the
flushing liquid should enter the seal housing at a low
pressure, with allowable pressure being up to 0.5
bar (7.5 PSI) maximum. Should the flush pressure be
higher, there is a risk of blowing out the lip seal, thus
allowing flush media leakage to atmosphere.
This most basic flush system, sometimes referred to
as quench, provides liquid to the atmosphere side of
the mechanical seal thereby flushing away any product
leakage. For the majority of pump models, the flushed
seal comprises of the same stationary and rotating
parts as the single seal, with the addition of a seal
housing having a flushing connection plus the afore-
mentioned lip seal.
Note:
Flush housing on SX/SX-UP, DuraCirc as well as OS
Twin Screw are integral to the rotor case/casing.
seal supplier for verification.
• Adhesive
• Caramel
• Detergent
• Fruit Juice Concentrate
• Gelatine
• Jam
• Latex
• Paint
• Sugar Syrup
• Toothpaste
• Yeast
Fig. 6.1g Single Flushed Mechanical Seal
4
3 2
9
5
1
8 6 7
10 11
Process media
Flush media
2. Rotary Seal ring
3. Spring
4. Drive ring
7. Impeller
8. Pump shaft
9. Backplate
10. Flush housing lip seal
11. Flush housing
104
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Sealing

Double Flushed Mechanical Seal
This seal arrangement is generally used with hostile
media conditions i.e., high viscosity, fluid is hazardous
or toxic. Additionally, it can also be used on applica-
tions where cleaning is via a SIP process, where the
steam condensate around the sealing area needs to
be at a pressure higher than 0.5 bar (7.5 PSI). The
double flushed seal used on Alfa Laval pump ranges is
basically two single mechanical seals mounted ‘back-
to-back’ (Fig. 6.1h). This seal generally comprises of
the same stationary and rotating parts as the single
seal for the majority of pump models, with the addition
of a seal housing having a flushing connection and/or
flushing tubes (dependent upon pump type).
Note:
Flush housing on SX/SX-UP, DuraCirc as well as Twin
Screw are integral to the rotor case/casing).
A compatible flushing liquid is pressurised into the seal
housing at a pressure of 1 bar (14 PSI) minimum above
the discharge pressure of the pump. This results in
the interface film being the flushing liquid and not the
pumped liquid. Special attention is required in select-
ing seal faces and elastomers.
It is also possible for a double seal to operate in low
pressure flush mode, i.e., where the flush pressure is at
a similar pressure to that used with single flushed seals
of 0.5 bar, or at a pressure lower than pump differen-
tial pressure. In this situation, the interface film will be
pumped media, rather than flushed media (Fig. 6.1i).
The arrangement in contact with the pumped fluid is
referred to as the ‘inboard seal’, and the seal employed
for the flushing liquid is referred to as the ‘outboard
seal’. For Alfa Laval centrifugal pumps the design of
the outboard seal differs to the inboard seal.
Fig. 6.1h Typical double flushed mechanical seal used in rotary lobe pumps
8
13 11 12
14 10
4
3 6
2 9
1 5 7
1. Stationary Seal ring inboard
2. Rotary Seal ring assembly
inboard
3. Wave Spring
4. Drive ring
5. Stationary Seal O-ring inboard
6. Rotary Seal O-ring inboard
7. Rotor
8. Shaft
9. Rotorcase
10. Rotary Seal ring assembly
outboard
11. Stationary Seal ring outboard
12. Rotary Seal O-ring outboard
13. Stationary Seal O-ring outboard
14. Flush housing
Process media
Flush media
105
6.0
Pump
Sealing

General Seal Face Operating Parameters
The tables above show general parameters regarding
viscosity and temperature, which should be noted
when selecting a mechanical seal.
Viscosity Seal Face Combination
Up to 4999 cP Solid Carbon v Stainless Steel
Solid Carbon v Silicon Carbide
Up to 24999 cP Inserted Carbon v Stainless Steel
Inserted Carbon v Silicon Carbide
Up to 149999 cP Silicon Carbide v Silicon Carbide
Above 150000 cP Consider Double Seals
Temperature Seal Face Combination
Up to 150° C
(302° F)
Inserted Carbon v Stainless Steel
Silicon Carbide v Silicon Carbide
Up to 200° C
(392° F)
Solid Carbon v Stainless Steel
Table 6.1b Table 6.1c
seal supplier for verification (Table 6.1b).
• Abrasive Slurries
• Chocolate
• Glucose
• Hazardous Chemicals
• PVC Paste
• Photographic Emulsion
• Resin
Fig. 6.1i Typical double flushed mechanical seal used in centrifugal pumps
3 2 6
5
8
9
1
11
7
4
13 14
12
10
1. Inboard Stationary Seal ring
2. Inboard Rotary Seal ring
3. Spring
4. Outboard Rotary Seal ring
5. Stationary inboard
Seal elastomer
6. Rotary Inbound Seal elastomer
7. Impeller
8. Pump shaft
9. Backplate
10. Outboard Stationary Seal ring
11. Flush housing
12. Rotary Outboard Seal elastomer
13. Stationary Outboard
Seal elastomer
14. Flush housing elastomer
Process media
Flush media
106
6.0
Pump
Sealing

Flushing Pipework Layout – PD pumps
It is recommended that seal flush pipework is de-
signed such that seals are flushed in parallel. This is to
ensure should one seal fail, then process media leak-
age does not enter the undamaged seal flush housing.
The suggested arrangement above is for single me-
chanical seals (Fig. 6.1j). If the pump is fitted with dou-
ble mechanical seals the pressure gauges and control
valves should be fitted on the outlet side of the system.
The choice of flushing liquid is dependent upon com-
patibility with the pumping media and overall duty con-
ditions i.e., pressure and temperature. Usually, water is
used for cooling and any water-soluble products.
On ATEX conforming pumps, seal flush pipework
should be designed so that seals are flushed in series,
rather than parallel. This should be done to eliminate
the risk of one seal dry running should the flush pipe-
work become blocked.
Flushing Pipework Layout – Centrifugal
pumps
Centrifugal pump flush pipework should be designed
such that inlet is at the bottom and outlet at the top, to
allow air venting, thereby reducing the risk of air pock-
ets developing, which could otherwise lead to localized
seal dry running (Fig. 6.1k).
Fig. 6.1k Typical flushing pipework layout for a centrifugal pump
Flush Media
Outlet
Flush Media
Inlet
Fig. 6.1j Typical flushing pipework layout for a rotary lobe pump
A
A: Pressure gauge
B: Control valve
C: Check valve
D: Isolation valve
A*
A
B
B*
B
C D Flush Inlet
Flush outlet to waste
Suggested visible
indication of flow
* Double mechanical seal only
1. Pressure gauge*
2. Control valve*
3. Suggested visible
indication of flow
4. Pressure gauge
5. Control valve
6. Check valve
7. Isolation valve
* Double mechanical seal only
2
3
4 5 6 7
1
107
6.0
Pump
Sealing

The below flow chart should be used for
guidance purposes only, as actual seal
selections should be verified by the seal
suppliers.
No
No
Yes
Yes
Obtain all Product/Fluid
and Performance data
Select Seal Type
Use Single Flushed Seal
Use Single Seal
Select Seal Materials
Select Seal Faces Select Elastomers
Use Double Flushed Seal
• Does fluid crystallise?
• Is cooling required?
• Will pump run dry?
• Is aseptic barrier required?
• Is fluid hazardous?
• Is fluid abrasive?
• Is fluid viscosity high?
• Is temperature high?
• Is aseptic barrier required?
• Check viscosity limitations
(see table 6.1b)
• Check temperature limitations
(see table 6.1c)
• Is fluid abrasive?
• Check chemical compatibility
• Check elastomer compatibility
(see guide in section 14.10)
• Check temperature limitations
Fig. 6.1l Seal selection process
Mechanical Seal Selection Process
The illustration describes the mechanical seal selection
process with relevant questions to be answered.
108
6.0
Pump
Sealing

6.2 Mechanical Seal Types
In Alfa Laval Pump Ranges
Seal Option Availability for Centrifugal Pumps
Pump Range External Mounting Internal Mounting
Single Single Flushed Double Flushed Single Single Flushed
LKH/LKH Evap   
LKH Prime  
LKH Multistage  
LKHPF  
LKHI  
LKH UltraPure  
LKH Prime UltraPure  
Solid C  
Solid C UltraPure  
FM  
GM 
Seal Option Availability for Rotary Lobe Pumps
Mechanical Seal Type Seal Name Pump Range
OptiLobe SRU SX-UP/SX
Single externally mounted R90
Hyclean


Single flushed externally mounted R90
Hyclean


Single internally mounted Easyfit
R00


Single flushed internally mounted Easyfit
R00


Double flushed externally mounted R90 
Double flushed internally mounted R00 
Note: R00 single flushed seal only available up to SX4
Table 6.2a
Table 6.2b
109
6.0
Pump
Sealing

Hyclean Type Mechanical Seals
The design of this seal incorporates a self-cleaning
feature in the form of the stationary seal element hav-
ing an angled seal face (see Fig. 6.2b). This permits an
enhanced cleaning action during CIP, as the cleaning
media is thrown off tangentially due to the angle.
Should EHEDG conformance be a user requirement,
this seal type should be selected.
R90 Type Mechanical Seals
This seal type is the standard choice for many hygienic
applications. A tried and trusted design, where easy
conversion between single, single flushed and double
seal variants is possible, without requiring any modifi-
cation to pump head components.
Shown above in Fig 6.2a is the R90 single seal. The
R90 single flushed and double seal variants are shown
in Fig 6.1f & 6.1h respectively.
Fig. 6.2b Hyclean single mechanical seal
8 4 6
2 9 7
1 3 5 10
2. Rotary Seal ring
3. Wave spring
4. Washer
5. Stationary Seal O-ring
7. Rotor
8. Shaft
9. Rotor case
10. Rotor spline sealing O-ring
Process media
Fig. 6.2a R90 single mechanical seal
1 5
7
10 9
2
6
3
11
4 8
Working length
2. Rotary Seal ring
3. Wave Spring
7. Rotor
8. Shaft
9. Rotorcase
Anti-rotation pin
11. Grub screw
Process media
110
6.0
Pump
Sealing

R00 Type Mechanical Seals
The R00 type mechanical seals (Fig. 6.2d), specifical-
ly designed for the SX and SX UltraPure rotary lobe
pump ranges, are fully front-loading seals and fully
interchangeable between seal variants, without
the need for additional housings or pump compo-
nent changes (Fig. 6.2c). Specialised seal setting of
the mechanical seal is not required, as the seal is
dimensionally set on assembly.
Seal faces are positioned directly in the fluid flow path,
thereby seeing full liquid velocity, ensuring optimal
cleaning during CIP cycle. All seals have controlled
compression joint elastomers at fluid/atmosphere
interfaces.
Fig. 6.2c SX pump head sealing
5 1 7
2
8
6
3
4
Fig. 6.2d R00 single mechanical seal
4
9 1 5 2 6 3
7
8
1. Front cover compression joint
2. Spline sealing cup seal
3. Rotary seal squad ring
4. Static seal cup seal
5. Rotor
6. Rotor case
7. Front cover
8. Rotor retainer
2. Rotary Seal ring
3. Wave Spring
4. Static seal ring
5. Static Seal cup seal
6. Rotary Seal Squad ring
7. Rotor
8. Rotorcase
9. Shaft
Process media
Process media
111
6.0
Pump
Sealing

EasyFit Mechanical Seals
This seal type is designed specifically for the OptiLobe
rotary lobe pump range. Fully front-loading by design,
simplifying service and interchangeable between vari-
ants, without pump modification, allows for increased
process flexibility (Fig. 6.2e). Specialised seal setting
of the mechanical seal is not required, as the seal is
dimensionally set on assembly. Seal faces are posi-
tioned directly in the fluid flow path, thereby seeing full
liquid velocity, ensuring optimal cleaning during CIP
cycle.
Fig. 6.2e OptiLobe Easyfit single mechanical seal in situ
10 9
1
5 2 6 4 3 7
8
2. Rotary Seal ring
3. Wave spring
5. Stationary L-cup seal
7. Rotor
8. Shaft
9. Rotor case
10. Stationary seal drive ring
Process media
112
6.0
Pump
Sealing

DuraCirc is the name for Alfa Laval’s range of circum-
ferential piston pumps.
The DuraCirc is available with two main seal designs,
the mechanical seal (Fig. 6.2f), and the O-ring seal
(Fig. 6.2i).
The mechanical seal is designed specifically for the
DuraCirc pump range. The single seal variant is fully
front loading by design, simplifying service. The design
of the DuraCirc is such that there is no separate flush
housing, with the flush chamber instead integrated
as part of the rotor case. This makes the conversion
from single-to-single flush seal via the simple addition
of a lip seal and from single to double seal via the
addition of outboard seal assembly. This makes seal
interchangeability very simple without pump modifica-
tion or the addition of housings, allowing for increased
process flexibility. In all seal variants specialised seal
setting is not required, as the seal is dimensionally set
on assembly. Seal faces are positioned directly in the
fluid flow path, thereby seeing full liquid velocity, ensur-
ing optimal cleaning during CIP cycle.
Seal Option Availability for Circumferential Piston Pumps
Fig. 6.2f DuraCirc single mechanical seal
8
9
4 3 1
5 2 6
10
7
2. Rotary Seal ring
3. Wave spring
4. Static assembly
5. Stationary seal squad ring
6. Rotary Seal square ring
7. Rotor
8. Shaft
9. Rotor case
10. Stationary seal ring
anti rotation pin
Process media
Fig. 6.2g DuraCirc single flushed mechanical seal
Fig. 6.2h DuraCirc double flushed mechanical seal
11 8
9
4 3 1
5 2 6
7
10
14
13 12
9
11
8 4 3 1
5 2 6
7
10
2. Rotary Seal ring
3. Wave Spring
4. Static assembly
5. Stationary Seal squad ring
6. Rotary Seal squad ring
7. Rotor
8. Shaft
9. Rotorcase
anti-rotation pin
11. Lip seal
1. Stationary Seal ring inboard
2. Rotary Seal ring inboard
3. Wave Spring
4. Static assembly
5. Stationary Seal squad ring inboard
6. Rotary Seal squad ring inboard
7. Rotor
8. Shaft
9. Rotorcase
anti-rotation pin
11. Stationary Seal O-ring outboard
12. Stationary Seal ring outboard
13. Rotary Seal ring outboard
14. Rotary Seal O-ring outboard
Process media
Process media
Flush media
Flush media
113
6.0
Pump
Sealing

Designed for users more familiar with operating pumps
fitted with O-ring seals, as with the mechanical seal
equivalent, the O-ring seal assembly is designed
specifically to fit in the DuraCirc pump range (Fig. 6.2i).
Conversion from mechanical seal to O-ring seal variant
is possible without any component modification.
The O-ring seal option also has the same advantages
as with the mechanical seal equivalent, in that the
single O-ring seal variant is fully front loading, there is
easy conversion from single to flushed O-ring by the
simple addition of a lip seal, without the need for hous-
ing or component modification (Fig. 6.2j). Additionally,
the O-ring is positioned directly in the fluid flow path,
thereby seeing full liquid velocity, ensuring optimal
cleaning during CIP cycle.
O-ring seal material options in FDA conforming EPDM
and FPM.
The O-ring in an O-ring seal is typically designed for
more frequent change than pumps fitted with me-
chanical seals, however wear is typically limited to the
O-ring itself. As it is an O-ring elastomer which is doing
the actual sealing, as opposed to a set of mechani-
cal seal faces, the recommended maximum running
speed is 300 rpm and operating pressure is 7 bar (102
PSI).
Fig. 6.2i DuraCirc O-ring seal
8
7
3
1 6 5
4
2
10
9
1. O-ring Seal housing
2. O-ring Seal sleeve
3. Dynamic O-ring
4. O-ring sleeve inner
5. O-ring sleeve outer
6. Housing O-ring
7. Rotor
8. Shaft
9. Rotor case
10. O-ring sleeve
anti rotation pin
Process media
Fig. 6.2j DuraCirc flushed O-ring seal
8
7
3
1 6 5
4
2
10
9
11
1. O-ring seal housing
2. O-ring seal sleeve
3. Dynamic O-ring
4. O-ring sleeve inner
5. O-ring sleeve outer
6. Housing O-ring
7. Rotor
8. Shaft
9. Rotorcase
10. O-ring
anti-rotation pin
11. Flush lip seal
Process media
Flush media
114
6.0
Pump
Sealing

full liquid velocity, ensuring optimal cleaning during CIP
cycle.
Seal options include single (FIg. 6.2k), single flushed
(FIg. 6.2l) and double variants (FIg. 6.2m).
The design of the OS Twin Screw pump is such that
the flush housing is integrated into the seal housing.
Conversion from single-to-single flushed or double
seal is easy, with no additional housings or component
re-work required.
Seal Option Availability for Twin Screw Pumps
The OS Twin Screw pump has a cartridge style seal
design, which means that the seal is fitted as a com-
plete one-piece assembly, rather than as individual
components.
The seal is truly front loading, making it very easy to fit.
The self-setting design allows very easy installation of
the seal, simply by sliding the seal onto the shaft until
it can be pushed no further and locking in place with
the seal retention pin. Additionally, the seal faces are
positioned directly in the fluid flow path, thereby seeing
Fig. 6.2k Twin Screw Single Mechanical Seal
4 9
8
1 10
7 6
5
11 3
2
1. Seal housing
2. Pump casing
3. Screw
4. Shaft
5. Sleeve
6. Rotary Seal face
7. Static Seal face
8. Seal housing (incl. coil springs)
9. Circlip
10. P-ring
11. Washer
Process media
Fig. 6.2l Twin Screw Flushed Mechanical Seal
Fig. 6.2m Twin Screw Double Mechanical Seal
4 9
8
1 10
7 6
5
11 3
2
12
1 2
3
4
5
7 6 10
11
10
8
9
12
16
15
14
13
1. Seal housing
2. Pump casing
3. Screw
4. Shaft
5. Sleeve
6. Rotary Seal face
7. Static Seal face
8. Seal housing (incl. coil springs)
9. Circlip
10. P-ring
11. Washer
12. Flush lip seal
1. Seal housing
2. Pump casing
3. Screw
4. Shaft
5. Rotary holder
6. Rotary Seal face inboard
7. Static Seal face inboard
8. Housing
9. Drive ring
10. P-ring
11. Washer
12. Static Seal face onboard
13. Rotary Seal face onboard
14. Drive ring (incl. coil springs)
15. Circlip
16. O-ring
Process media
Process media
115
6.0
Pump
Sealing

This section shows how to size an
Alfa Laval pump from product/fluid
and performance data given, sup-
ported by relevant calculations and
worked examples with a simple
step by step approach.
116
7.0
Pump
Sizing

Pump Sizing
7
.0
117
7.0
Pump
Sizing

See chapter 2 for detailed
descriptions of Product/Fluid
data and Performance data.
7.1 General Information Required
In order to correctly size any type of pump some
essential information is required as follows:
Product/Fluid Data
• Fluid to be pumped
• Viscosity
• SG/Density
• Pumping temperature
• Vapor pressure
• Solids content (max. size and concentration)
• Fluid behavior (i.e., Newtonian or Pseudoplastic
etc.)
• Is product hazardous or toxic?
• Does fluid crystallize in contact with atmosphere?
• Is CIP required and if so what temperature and
performance data if needs to be carried out with
our pump?
Performance Data
• Capacity (flow rate)
• Discharge head/pressure
• Suction condition (flooded or suction lift) NPSHa
Site Services Data
• Power source (electric, air, diesel, petrol
or hydraulic). If electric – motor enclosure
and electrical supply
• Seal flushing fluid
Specific requirements
• EHEDG/3A
• ATEX/Explosion zone
• Port Orientation
• Surface Finish
• Traceability
– Use of frequency drive/VFD
In an ideal situation all the above criteria should be
known before sizing a pump – however, in many
instances not all this information is known and made
available. In such cases to complete the sizing pro-
cess, some assumptions may need to be made based
upon application knowledge, experience etc. These
should be subsequently confirmed, as they could be
critical to satisfactory installation and operation.
If you have access to our Online ALiCE selection
system (other systems as PUMP-FLO®
can also be
used) the acquired data together with assumptions
can be
entered and the system will advise which pumps can
be used for the specific duty and gives the option to
sort by the most important factors for the customer
whether this is efficiency, purchase price or other
factors.
If you have access to ALiCE and want to select from
there then please go through our Webinars on sizing
and configuration in our learning portal.
For calculating the correct size pump and to make
qualified assumptions the following will assist in
optimal sizing.
118
7.0
Pump
Sizing

7.2 Power
This can be calculated as follows:
Hydraulic Power (W) = Q x H x ρ x g Where:
Q = Capacity (m3
/s)
H = Total Head/Pressure (m)
)
g = Acceleration due to Gravity (m/s2
)
Other forms of this equation can be as follows:
Hydraulic Power (kW) = Q x H
k
Where:
Q = Capacity
H = Total Head/Pressure
k = Constant (dependent upon units used)
Therefore
Hydraulic Power (kW) = Q x H
k
Where:
H = Total Head/Pressure (bar)
k = 600
or
Hydraulic Power (hp) = Q x H
k
Where:
H = Total Head/Pressure (PSI)
k = 1715
All of the system energy requirements and the energy
losses in the pump must be supplied by a prime mover
in the form of mechanical energy. For Alfa Laval pumps
this will be an electrical motor, so it will be called motor
from here. The rate of energy input needed is defined
as power and is expressed in watts (W) – for practical
purposes, power within this handbook is expressed in
kilowatts (kW), i.e., watts x 103
.
7.2.1 Hydraulic Power
The theoretical energy required to pump a given
quantity of fluid against a given total head is known
as hydraulic power, hydraulic horsepower or water
horsepower.
119
7.0
Pump
Sizing

Required Power = ω x T Where:
ω = Shaft Angular Velocity
T = Shaft Torque
Shaft Angular Velocity = ω = V x r (see Fig. 7.2.2a) Where:
ω = Shaft Angular Velocity
V = Velocity
r = Radius
And is related to Hydraulic Power by:
Required Power = Hydraulic Power
Efficiency (100% = 1.0)
7.2.2 Required Power
The required power or brake horsepower is the power
needed at the pump shaft. This is always higher than
the hydraulic power due to energy losses in the pump
mechanism (friction loss, pressure loss, seals etc.) and
is derived from:
The appropriate motor power must be selected. This
will generally be the nearest motor rated output power
above the required power.
Fig. 7.2.2a Shaft angular velocity
r = Radius
V = Velocity
120
7.0
Pump
Sizing

Torque can be calculated as follows:
Torque (Nm) = Required power (kW) x 9550
Pump speed (rev/min)
or
Torque (Kg-m) = Required power (kW) x 974
or
Torque (ft lb) = Required power (hp) x 5250
The power requirements for
mechanical devices such as
pumps and pump drives are
best expressed in terms of
torque and speed.
7.2.3 Torque
Torque is defined as the moment of force required to
produce rotation and is usually expressed in units of
Nm (Newton meter), Kg-m (Kilogram meter) or ft lb
(foot pound).
It should be noted that positive displacement pumps
are basically constant torque machines and therefore
it is important that the transmission chosen is capa-
ble of transmitting the torque required by the pump.
This is particularly important for variable speed drives
which should be selected initially on torque rather than
power.
Always be aware that torque requirement can be
higher for the minimum speed than for the higher
speed when you have a large span in speed.
121
7.0
Pump
Sizing

7.2.4 Efficiency
Total Efficiency
Total efficiency is typically used on centrifugal pump
to describe the relationship between input power at
the pump shaft and output power in the form of water
horsepower. The term ‘mechanical efficiency’ can
also be used to describe this ratio. Total efficiency,
designated by symbol η comprises of three elements,
Hydraulic Efficiency (ηh), Mechanical Efficiency (ηm) and
Volumetric Efficiency (ηv) which are described below:
Hydraulic Efficiency
The term hydraulic efficiency is used on centrifugal
pumps to describe one of the three elements of
centrifugal pump total efficiency as described above.
Where
Hydraulic Efficiency (ηh) =
Pump Head Loss (m) x 100%
Total Head (m)
The pump head losses comprise of the shock loss
at the eye of the impeller, friction loss in the impeller
blade and circulation loss at the outlet side of the
impeller blades.
Mechanical Efficiency
This term is used on all centrifugal and positive
displacement pump types, and is typically used to
describe the losses associated with the transfer of
energy from the motor through a mechanical system
to the pumped liquid.
Where
Mechanical Efficiency (ηm ) =
1 - Pump mechanical losses x 100%
Required power
Pump mechanical losses refers to the friction losses
associated with bearings, seals and other contacting
areas within the pump.
Volumetric Efficiency
This term is used on all centrifugal and positive dis-
placement pump types. It is most commonly used to
compare the performance of a number of pump types,
where accurate geometric data is available.
For centrifugal pumps,
Volumetric Efficiency (ηv) = Q x 100%
Q + QL
Where: Q = Pump capacity
QL = Fluid losses due to leakage through
the impeller casing clearances
For positive displacement pumps the term volumetric
efficiency (ηv) is used to compare the displacement
of the pump against the capacity of the pump. The
displacement calculation (q) per revolution for positive
displacement pumps involves calculating the volume of
the void formed between the rotating element and the
fixed element of the pump. This is then multiplied by
the number of voids formed by a rotating element per
revolution of the pump’s drive shaft and by the number
of rotors in the pump.
For rotary lobe pumps,
Volumetric Efficiency (ηv) = Q x 100%
q
Where: Q = Pump capacity
q = Pump displacement
122
7.0
Pump
Sizing

Q = q x ηv x 60 x n
100
Where:
n = Pump Speed (rev/min)
Q = Capacity (m3/h)
q = Pump Displacement (m3/100 rev)
ηv = Volumetric Efficiency (100% = 1.0)
n = Q x 100
q x ηv x 60
Where:
Q = Capacity (m3
/h)
q = Pump Displacement (m3
/100 rev)
or
Q = q x ηv x n
100
Where:
q = Pump Displacement (US gal/100 rev)
ηV = Volumetric Efficiency (100% = 1.0)
Rotary lobe are generally efficient pumps and even at
viscosity of 100 cP the volumetric efficiency of most
pumps is approximately 90% for low pressure duties.
At lower viscosities and/or higher pressures the volu-
metric efficiency will decrease due to slip as described
in 7.6.1. Above 1000 cP, volumetric efficiency can be
as high as 95–99% for the Rotary lobe pumps.
Looking at Circumferential Piston pumps these are
highly efficient pumps with a volumetric efficiency of
95–99% at viscosities as low as 15 cP.
While Twin Screw pumps can easily handle viscosities
from 1 to 1000000 cP the efficiency will be around
80% of the rotary lobe pumps for the higher viscous
products.
The pump speed should always be selected according
to the product and how gentle it needs to be treated,
how high the viscosity is, how many particles it has
etc.
When the maximum speed has been selected for
the Rotary lobe/Circumferential Piston pump and the
viscosity is high enough to have almost full volumetric
efficiency, the capacity of the pump can be calculated
according to the following formulas. Rearranging the
formula will calculate the maximum speed. Full speed
is rarely recommend as the mechanical losses inside
the pump will cause vibration and noise.
123
7.0
Pump
Sizing

Pump Efficiency ηp = Water horsepower x 100%
Required power
or
Pump Efficiency ηp = Q x H x ρ x g
ω x T
Where:
Q = Capacity (m3
/s)
ρ = Fluid Density (lb/ft3
)
)
ω = Shaft Angular Velocity (rad/s)
T = Shaft Torque (Nm)
or
Pump Efficiency ηp = Q x H x ρ x g
ω x T x 3960
Where:
Q = Capacity (US GPM)
H = Total Head/Pressure (ft)
ρ = Fluid Density (lb/ft3
)
g = Acceleration due to Gravity (ft/s2
)
ω = Shaft Angular Velocity (rad/s)
T = Shaft Torque (lb/ft)
Pump Efficiency
The term pump efficiency is used on all types of
pumps to describe the ratio of power supply to the
drive shaft against water horsepower (the power
available to move the liquid without losses).
Overall Efficiency
Overall efficiency is a term used to describe and
compare the performance of all types of pumps.
Overall efficiency considers the efficiency of both the
prime mover and the pump, and is sometimes known
as the wire to water/liquid efficiency where the prime
mover is an electric motor.
Overall Efficiencyoa = Water horsepower x 100%
Drive power
The higher the efficiency the less power will be lost to
vibrations, heat generation etc. This makes the pump
more sustainable and gives longer service intervals.
124
7.0
Pump
Sizing

7.3.1 Flow Curve
A centrifugal pump should always be sized from a
pump flow curve or a pump selection program. Most
pump flow curves are based on tests with water. It
is difficult to determine general curves for fluids with
viscosities different from water and therefore in these
instances it is recommended to use a pump selection
program.
A pump flow curve specifies the connection between
Capacity Q, Head H, Required Power P, Required
NPSH and Efficiency (η).
Hydraulic Losses
The connection between the capacity and the theore-
tical head of the pump is shown by means of a straight
line, which decreases at a higher capacity (see Fig.
7.3.1a).
The actual head of a pump is, however, lower than the
theoretical head due to hydraulic losses in the pump,
which are friction loss, pressure loss and slip.
The connection between the capacity and actual head
is consequently specified by means of a curve which
varies depending on the design of the impeller.
Different Pump Characteristics
The Capacity Q and Head H curve of a centrifugal
pump will vary depending upon the impeller vane
design (see Fig. 7.3.1.b).
These fulfil different requirements and are well suited
for flow control where only one parameter is to be
changed (see section 7.3.2).
Curve 1 covers a wide range of heads without large
changes to capacity.
Curve 3 covers a wide range of capacities without
large changes to head.
Middle curve has a moderate change in both capacity
and head.
Fig. 7.3.1a Hydraulic losses
Fig. 7.3.1b Curves for Q and H
H Theoretical Head
Hydraulic Losses
Actual Head
Q
H
Q
3
1
125
7.0
Pump
Sizing

Capacity Q, Head H, Power P and Efficiency
Curves
In principle the duty point of a pump can be situated
at any point on the Q – H curve. (Fig. 7.3.1c)
The efficiency of the pump will vary depending on
where the duty point is situated on the Q – H curve.
The efficiency is usually highest near the centre of the
curve.
The power curve of the centrifugal pump increases at
a higher capacity.
NPSHr Curve
(see section 2.2.4 on NPSHa calculation)
The NPSHr curve increases at higher capacity (see
Fig. 7.3.1d). This should be used to ascertain the
NPSHr of the pump. It is important that NPSHa of the
system exceeds the NPSHr of the pump.
Viscosity Effect
Fluid viscosity will affect capacity, head, efficiency and
power (see Fig. 7.3.1e).
• Capacity, head and efficiency will decrease at
higher viscosities
• Required power will increase at higher viscosities
Density Effect
Fluid density will affect the head and required power
which both increase proportionally at higher density
(see Fig. 7.3.1f). When head increases capacity will go
down if VFD is not used.
Fig. 7.3.1c Curves for Q, H, P and ρι
Fig. 7.3.1e Effects on Q, H and η
Fig. 7.3.1d NPSHr curve
Fig. 7.3.1f Effects on Q, H and η
H
Pcentr.
Q
H
Q
NPSHr
Q
P
Q
7.0
Pump
Sizing

Example:
Product/Fluid Data:
Fluid to be pumped - Water
Viscosity - 1 cP
SG - 1.0
Pumping temperature - 20° C
Performance Data:
Capacity - 15 m3
/h
Total head - 25 m
Electrical supply - 220/380v, 50 Hz
How to use the Flow Curve
The flow curve consists of three different curves:
• Head as a function of capacity (Q – H curve)
• Required power as a function of capacity
(Q – P curve)
• Required NPSH as a function of capacity
(Q – NPSHr curve)
Although illustrated here the efficiency is not shown
on the published flow curves but can be determined
from the required power on the flow curve and formula
in section 7.2 when the duty point is known and the
hydraulic power can be calculated and compared to
the power from the curve. Efficiency is shown in the
ALiCE sizing program.
The Q – H and Q – P curves are specified for different
standard impeller diameters so that a correct duty
point can be determined. This is not applicable to
the LKH-Multistage pumps as the impeller diameters
cannot be reduced.
The curves on the flow curve are based on tests with
water at 20° C (68° F) with tolerances of ± 5%. It is
recommended to select the pump by means of a
pump selection program if the fluid to be pumped
has other physical properties.
The optimum is to select the pump with the best return
of investment (ROI), for the required duty point (15
m3
/h, 25 m). This can also require information about
running hours and expected lifetime so again assump-
tions might need to be made.
127
7.0
Pump
Sizing

Step 1 – Find Appropriate Curve
Locate a flow curve for the required pump type that
covers the duty point. For this particular example a
flow curve of a centrifugal pump type LKH-10 with
3000 rev/min synchronous speed at 50 Hz is selected
(see Fig. 7.3.1g).
Step 2 – Look at Q – H curve
• Locate the capacity (15 m³/h) on the Q-scale
• Start from this point and follow the vertical line
upwards until it intersects with the horizontal line
indicating the required head (25 m) on the H-scale
• This duty point does not contact any curve corre-
sponding to a certain impeller diameter. Therefore,
the nearest larger size impeller diameter should be
selected, in this case 150 mm. Alternatively ask to
get the impeller reduced to 145 mm
• The head will then be 28 m
• The selected head (28 m) should be checked
regarding the lower tolerance of the curve to
ensure that it is at least the required 25 m
• In this case the head should be reduced by 5%
being the curve tolerance
• The head will then be a minimum of 26.6 m greater
than 25 m, thus satisfactory
Step 3 – Look at Q – P curve
• The next step in selecting the pump is to follow
the vertical capacity line (15 m3
/h) downwards
until it intersects with the power curve for the
150 mm impeller
• A horizontal line to the left of the intersection
indicates a required power of 2.0 kW
• For a LKH centrifugal pump a safety factor of 5%
for motor losses must be added, resulting in a total
required power of 2.1 kW
• Consequently a 2.2 kW motor can be used
Step 4 – Look at Q – NPSHr curve
• Finally the vertical capacity line (15 m3
/h) is followed
up to the NPSHr curve (green)
• The intersection corresponding to the 150 mm
impeller is located
• A horizontal line to the right of the intersection
indicates that NPSHr is approx. 0.8 m
128
7.0
Pump
Sizing

Fig. 7.3.1g Example
40
35
30
25
28
20
15
10
5 5
10
5 20
15 30
25 40
35 50
45 60
55 70
65 75
Q (m3
/h)
10
5
1
2
3
4
20
15 30
25 40
35 50
45 60
55 70
65 75
Q (m3
/h)
A
A = 110
B = 120
C = 130
D = 140
E = 150
F = 160
G = 163
A = 110
B = 120
C = 130
D = 140
E = 150
F = 160
G = 163
B C
D
E
F
G
A
B
C
D
E
F
G
NPSHr (m)
H (m)
P (kW)
129
7.0
Pump
Sizing

7.3.2 Flow Control
Duty Point
The duty point of a pump is the intersection point
between the pump curve and the process curve.
Pump curve – this specifies the connection between
head H and capacity Q (see section 7.3.1).
Process curve – this specifies the connection between
the total pressure drop (L ∆H) in the process plant and
the capacity (Q) (see Fig. 7.3.2a).
The process curve is determined by varying the ca-
pacity so that different pressure drop (∆H) values are
obtained. The shape of the process curve will depend
on the process design (i.e., layout, valves, filters etc.).
The duty point of a pump can change due to chang-
es in the conditions of the process plant (changes in
head, pressure drops etc.). The pump will automati-
cally regulate the capacity to meet the new conditions
(see Fig. 7.3.2b and 7.3.2c).
Capacity: Q1 Q2 Q3 Q4 Q5 Q6
Pressure drop: DH1 DH2 DH3 DH4 DH5 DH6
It is possible to compensate for the change of duty
point by means of flow control that can be achieved as
follows:
• Reducing the impeller diameter
(not for Multistage pumps)
• Throttling the discharge line
• Controlling the pump speed
Due to flow control it is possible to achieve optimum
pump efficiency at the required capacity resulting in
the most economical pump installation.
Fig. 7.3.2a Process curve
Fig. 7.3.2b Changes in pressure drop Fig. 7.3.2c Changes in required head
H
1
2
3 4
5
6
Q
H
2
1
Q
H
2
1
Q
130
7.0
Pump
Sizing

Speed/Capacity: Q1 = n1 ⇒ n2 = n1 x Q2
Q2 n2 Q1
[rev/min]
Speed/Head: H1 = n1
2
⇒ n2 = n1 x
H2 n2
2
[rev/min]
Speed/Power P1 = n1
3
⇒ n2 = n1 x
P2 n2
3
[rev/min]
√
3 P2
P1
√H2
H1
√c-b
a-b
Reducing Impeller Diameter
Reducing the impeller diameter can only be carried
out for centrifugal pumps. This will reduce the capacity
and the head.
Centrifugal Pump
The connection between Impeller Diameter (D),
Capacity (Q) and Head (H) is shown in Fig. 7.3.2d:
1. Before reducing
2. After reducing – the duty point moves towards point
2 when reducing the impeller diameter
If the impeller speed remains unchanged, the connec-
tion between Impeller Diameter (D), Capacity (Q), Head
(H) and Required Power (P) is shown by the following
formulas: The formula is for guidance purpos-
es only. It is recommended to add a
safety factor of 10–15% to the new
diameter.
Most pump flow curves show characteristics for
different impeller diameters to enable the correct
impeller diameter to be selected.
Reducing the impeller diameter by up to 20% will not
affect the efficiency of the pump much. If the reduction
in impeller diameter exceeds 20%, the pump efficiency
will decrease.
The impeller diameter is reduced to D2 by means of
the following formula:
D2 = D1 x [mm]
Where:
D1 = Standard Diameter before Reducing
a = Maximum Duty Point
b = Minimum Duty Point
c = Required Duty Point
Fig. 7.3.2d Reducing impeller diameter
H
2
1
D1
D2
Q1
Q2
H2
H1
Q
131
7.0
Pump
Sizing

Throttling Discharge Line
Throttling the discharge line will increase the resistance
in the process plant, which will increase the head and
reduce the capacity.
The connection between Capacity (Q) and Head (H)
when throttling is shown in Fig. 7.3.2e.
1. Before throttling
2. After throttling, the duty point moves towards
point 2
Throttling should not be carried out in the suction line
as cavitation can occur.
Also throttling will reduce the efficiency of the process
plant ∆H shows the ‘waste’ of pressure at point 2 to
overcome the throttling.
Controlling Pump Speed
Changing the impeller speed will change the cen-
trifugal force created by the impeller. Therefore, the
capacity and the head will also change.
The connection between Capacity (Q) and Head (H)
when changing the impeller speed is shown in Fig.
7.3.2f.
1. Before reducing impeller speed
2. After reducing impeller speed. The working point
moves towards point 2 when reducing the impeller
speed
Fig. 7.3.2e Throttling discharge line Fig. 7.3.2f Controlling pump speed
H
2
1
Q1
Q2
H2
H1
H
Q
H
2
1
Q1
Q2
H2
H1
n1
n2
Q
132
7.0
Pump
Sizing

The most common form of
speed control is by means
of a frequency converter
(see section 9.10).
Speed/Capacity: Q1 = n1 ⇒ n2 = n1 x Q2
Q2 n2 Q1
[rev/min]
Speed/Head: H1 = n1
2
⇒ n2 = n1 x
H2 n2
2
[rev/min]
Speed/Power P1 = n1
3
⇒ n2 = n1 x
P2 n2
3
[rev/min]
√
3 P2
P1
√H2
H1
If the impeller dimensions remain unchanged, the
connection between Impeller Speed (n), Capacity (Q),
Head (H) and Required Power (P) is shown by the
following formulas:
As shown from the above formulas the impeller speed
affects capacity, head and required power as follows:
• Half speed results in capacity x 0.5
• Half speed results in head x 0.25
• Half speed results in required power x 0.125
Speed control will not affect the efficiency much
providing changes do not exceed 20%.
7.3.3 Alternative Pump Installations
Pumps Coupled in Series
It is possible to increase the head in a pump installa-
tion by two or more pumps being coupled in series
(see Fig. 7.3.3a).
The Capacity (Q) will always be constant throughout
the pump series (see Fig. 7.3.3b).
The head can vary depending on the pump sizes.
The outlet of pump 1 is connected to the inlet of
pump 2.
Pump 2 must be able to withstand the outlet head
from pump 1.
Fig. 7.3.3a Principle of connection
2
H = H1 + H2 Q = Constant
1
H2
H1
133
7.0
Pump
Sizing

If two different pumps are connected in series, the
pump with the lowest NPSH value should be installed
as the first pump (for critical suction conditions).
The capacity in the pump installation should not
exceed the max. capacity of the smallest pump.
Otherwise, there will be a pressure drop in the smallest
pump.
7.3.4 Pumps Coupled in Parallel
It is possible to increase the capacity in a pump
installation by two or more pumps coupled in parallel
(see Fig. 7.3.3c).
The Head (H) will always be constant in the pump
installation. The capacity can vary depending on the
pump sizes. (See Fig. 7.3.3d)
A multi-stage centrifugal pump is in principle several
pumps that are coupled in series but built together as
one pump unit.
Fig. 7.3.3b Head of pumps in series Fig. 7.3.3c Principle of connection
Fig. 7.3.3d Connection of two similar pumps Fig. 7.3.3e Connection of two different pumps
H
Q
H2
H1
Q
Q1
Q3
Q2
Q
1
2
Q3 = Q1 + Q2 H = Constant
H
1+2
1.2
Q1 = Q2
H
Q
H
2
1 1+2
Q1 Q2
Q
134
7.0
Pump
Sizing

The pumps receive the fluid from the same source and
have a common discharge line.
When the capacity is increased by means of pumps
coupled in parallel, the equipment and pressure drop
in the installation must be determined according to the
total capacity of the pumps (see Fig. 7.3.3f).
For two different pumps, If the capacity Q1 is smaller
than the capacity Q2, it is possible to install a non-
return valve in the discharge line of pump 1 to avoid
pump 2 pumping fluid back through pump 1 (see Fig.
7.3.3e).
Equally it is important to install the pumps with same
pipe size etc. so one pump does not take all the flow
and “starve” the other which could result in cavitation.
Fig. 7.3.3f Connection of two different pump sizes
Q1
Q2
1
2
Q1Q2
135
7.0
Pump
Sizing

7.4 Worked Examples – Centrifugal Pump Sizing
Metric units
7.4.1 Example 1
The following example in Fig. 7.4.1a shows a pump to
be sized for a typical brewery process.
The pump is required to handle Wort from the
Whirlpool to the Fermentation vessel.
Fig. 7.4.1a Example 1
Yeast
Yeast pitching
Cooling
Wort pump
Whirlpool
80 m
0.6 bar
(pressure vessel)
21
m
Fermentation
CIP
CO2
CO2
O2
CIP
CO2
CO2
7.0
Pump
Sizing

All the data has been given
by the customer.
Product/Fluid data:
Fluid to be pumped - Wort
Viscosity - 1 cP
Performance data:
Capacity - 40 m3
/h
Discharge - via 80 m of 101.6 mm dia.
tube, plus a given number
of bends, valves and a
plate heat exchanger with
∆pPHE 1.6 bar.
Static head in Fermenting
vessel = 21 m.
Pressure in Fermenting
vessel = 0.6 bar
Suction - 0.4 m head, plus a given
number of bends and
valves
Site Services data:
Electrical supply - 400v, 50 Hz
As described in section 7.1 in order to correctly size
any type of pump, some essential information is re-
quired such as Product/Fluid data, Performance data
and Site Services data.
137
7.0
Pump
Sizing

Total head
Total Discharge Head Ht = ht + hft + pt Where:
ht = Static Head in Fermentation Vessel
hft = Total Pressure Drop in Discharge Line
pt = Pressure in Fermentation Vessel
Therefore:
ht = 21 m
hft = Pressure Drop in Tube ∆ptube
+ Pressure Drop in Bends and Valves ∆p
+ Pressure Drop in Plate Heat Exchanger ∆pPHE
∆ptube (from curve shown in 14.5) = 1.5 m
(1.8 m loss per 100 m)
∆p is calculated to be 5 m
∆pPHE is given as 1.6 bar = 16 m
hft = 1.5 + 5 + 16 m = 22.5 m
pt = 0.6 bar = 6 m
Ht = ht + hft + pt = 21 + 22.5 + 6 m = 49.5 m (4.95 bar)
Total suction head Hs = hs - hfs + ps Where:
hs = Static Suction Head in Whirlpool
hfs = Total Pressure Drop in Suction Line
ps = Pressure in Whirlpool (open tank)
Therefore:
hs = 0.4 m
hfs = Calculated to be 1 m
ps = 0 (open tank)
Hs = hs - hfs + ps = 0.4 - 1 + 0 m = - 0.6 m (- 0.06 bar)
Total head H = Ht - Hs = 49.5 - (- 0.6) = 50.1 m (5.01 bar)
Before sizing a pump, it will be necessary to determine
the total head and NPSHa. The theory, including the
different formulae regarding these parameters is more
specifically described in section 2.2.2 and 2.2.4.
Fig. 7.4.1b Typical suction / Discharge Head set-up
h
t
h
s pt
ps
hfs hft
138
7.0
Pump
Sizing

NPSHa
NPSHa = Pa + hs - hfs - Pvp Where:
Pa = Pressure Absolute above Level
of Fluid in Whirlpool Tank
hs = Static Suction Head in Whirlpool Tank
Pvp = Vapour Pressure of Fluid
Therefore:
Pa = 1 bar (open tank) = 10 m
hs = 0.4 m
Pvp = 0.70 bar a (from table 14.4a) = 7 m
NPSHa = 10 + 0.4 - 1 - 7 (m) = 2.4 m
For this particular example, pump sized would be as
follows:
Pump Model - LKH-25
Impeller size - 200 mm
Speed - 2940 rev/min
Capacity - 40 m3
/h
Head - 50.1 m (5.01 bar)
Efficiency - 63.1%
NPSHr - 1.4 m
Motor size - 11 kW
Actual pump sizing can be made using pump perfor-
mance curves or a pump selection program. The per-
formance curves are, however, not suitable if the fluid
to be pumped has physical properties (i.e., viscosity)
different from water. In this particular example both the
pump performance curves and pump selection pro-
gram can be used. The performance curve selection
procedure is more specifically described in section
7.3.1.
Cavitation check
NPSHa should be greater than NPSHr i.e., 2.4 m 1.4
m, i.e., no cavitation will occur.
The recommended shaft seal type based upon Alfa
Laval application experience and guidelines would be
a double mechanical seal with carbon/silicon carbide
faces and EPDM elastomers.
139
7.0
Pump
Sizing

Special Note
The discharge head (ht2) is lower when the pump starts
filling the fermenting vessel compared to the discharge
head (ht1
) when the vessel is full. The reduction of
the discharge head will result in higher flow. This will
reduce the NPSHr and can therefore lead to cavitation.
Another risk is that the larger capacity and thereby
larger power consumption can cause overloading of
the motor (see Fig. 7.4.1c).
Cavitation can be avoided by reducing the pump
speed (reducing NPSHr), i.e., by means of a frequency
converter, or by throttling the discharge line (increasing
head). The flow control method is more specifically
described in section 7.3.2.
Adjustment
In this example the pump is sized by the pump selec-
tion program which results in exact impeller diameter
of 200 mm, so that the selected duty point is as close
to the required duty point as possible.
The pump is sized with a standard impeller diameter
if using the performance curve. In this case it may be
necessary to adjust the selected duty point by means
of flow control.
It is important to note that the selected head has a
tolerance of ± 5% due to the tolerance of the pump
curve. Consequently, there is a risk that the pump
capacity will differ from the selected. If the required
capacity is the exact value of the process, it is recom-
mended to adjust to the required duty point by means
of flow control. Flow control method is more specifical-
ly described in section 7.3.2.
1: Full vessel
2: Empty vessel
Fig. 7.4.1c Q - H charateristic when changing valves
H
ht1
ht2
2
1
Q
Q1 Q2
7.0
Pump
Sizing

7.4.2 Example 2
The following example in Fig. 7.4.2a shows a
centrifugal pump to be sized for a typical dairy
process.
Pump ‘A’ is a Raw Milk pump in connection with
a pasteuriser. The raw milk is pumped from a
Balance Tank to a Separator via the preheating
stage in the plate heat exchanger.
Separator
P = 1.5 bar
Standardised Milk
PHE
Pump ‘A’
Balance Tank
CIP
Milk out
142
7.0
Pump
Sizing

Product/Fluid data:
Fluid to be pumped - Raw Milk
Viscosity - 5 cP
Performance data:
Capacity - 30 m3
/h
Discharge - via 5 m of horizontal 76
mm dia. tube, plus a given
number of bends, valves
and a plate heat exchang-
er with ∆pPHE 1 bar.
Inlet pressure for the sep-
arator = 1.5 bar
Suction - 0.1 m head, plus a given
number of bends and
valves
Site Services data:
by the customer.
143
7.0
Pump
Sizing

Total head
ht = Static Head to Separator
pt = Pressure in Separator
Therefore:
ht = 0 m (no static head – only horizontal tube)
+ Pressure Drop in Plate Heat Exchanger pPHE
∆ptube (from curve shown in 14.5) = 0.2 m
(4 m loss per 100 m)
∆p is calculated to be 0.1 m
∆pPHE is given as 1.0 bar = 10 m
hft = 0.2 + 0.1 + 10 m = 10.3 m
pt = 1.5 bar = 15 m
Ht = ht + hft + pt = 0 + 10.3 + 15 m = 25.3 m (2.53 bar)
hs = Static Suction Head in Balance Tank
ps = Pressure in Balance Tank (open tank)
Therefore:
hs = 0.1 m
hfs = Calculated to be 0.4 m
ps = 0 (open tank)
Hs = hs - hfs + ps = 0.1 - 0.4 + 0 m = - 0.3 m (- 0.03 bar)
Total Head H = Ht - Hs = 25.3 - (- 0.3) = 25.6m (2.56 bar)
the total head and NPSHa (Fig. 7.4.2b). The theory,
including the different formula regarding these param-
eters is more specifically described in section 2.2.2
and 2.2.4.
h
t
h
s pt
ps
hfs hft
144
7.0
Pump
Sizing

NPSHa
Pa = Pressure Absolute above Level
of Fluid in Balance Tank
Therefore:
hs = 0.1 m
Pvp = At temperature of 5° C this is taken as being
negligible i.e., 0 bar a (0.008 bar) = 0 m
NPSHa = 10 + 0.1 - 0.4 - 0 (m) = 9.7 m
follows:
Pump Model - LKH-20
Capacity - 30 m3
/h
Head - 25.6m (2.56 bar)
Efficiency - 62.7%
NPSHr - 1.4 m
Motor size - 4 kW
As the fluid to be pumped has physical properties (i.e.,
viscosity) different from water, the pump performance
curves should not be used, and actual pump sizing
should be made using the pump selection program.
Cavitation check
NPSHa should be greater than NPSHr i.e., 9.7 m 1.4
m, i.e., no cavitation will occur.
a single mechanical seal with carbon/silicon carbide
145
7.0
Pump
Sizing

Product/Fluid data:
Fluid to be pumped - CIP return
Viscosity - 1 cP
Pumping temperature - 5° C – 90° C
Performance data:
Capacity - 30 m3
/h
Discharge - via 5 m of horizontal 76
mm dia. tube, plus a given
number of bends, valves
er with ∆pPHE 1 bar as well
as 1.5 bar over a separator
Suction - 0.5 m static head, plus a
given number of bends
and valves all together
with a friction loss of 0.5 m
Site Services data:
7.4.3 Example 3
A CIP return pump is to be sized for an application for
the following details given by the customer:
146
7.0
Pump
Sizing

Total head
Total Discharge head Ht = ht + hft + pt
Taken from Example 2 = 25.3 m (2.53 bar)
Total Suction Head Hs = hs - hfs + ps Where:
Therefore:
hs = 0.5 m
ps = 0 (open tank)
Hs = hs - hfs + ps = 0.5 - 0.5 + 0 m = 0 m = (0 bar)
Total head H = Ht - Hs = 25.3 - 0 = 25.3 m (2.53 bar)
NPSHa
Pa = Pressure Absolute above Level of Fluid
in Balance Tank
Therefore:
hs = 0.5 m
Pvp = At temperature of 90° C
(important to check at highest
temperature. Table 14.4)
= 0.7 bar = 7 m
NPSHa = 10 + 0.5 - 0.5 - 7 (m) = 3 m
147
7.0
Pump
Sizing

Using a sizing program we get the option of a LKH
Prime-20:
Pump Model - LKH Prime-20
Capacity - 30 m3
/h
Head - 25.3 m (2.53 bar) - it is
important not to oversize
as air evacuation capability
diminish below 2800 rpm
Efficiency - 49.9%
NPSHr - 4.1 m
Power absorbed - 4.4 kW
Motor size - 5.5 kW
Checking another size pump, LKH-40, the option is
the below:
Capacity - 30 m3
/h
Head - 25.3 m (2.53 bar) - it is
Efficiency - 34.6%
NPSHr - 2.5 m
Power absorbed - 6.1 kW
Motor size - 7.5 kW
Cavitation check
NPSHa should be greater than NPSHr i.e.,
3 m 2.5 m.
This will work. However, the efficiency is lower resulting
in higher power consumption so it is worth checking if
temperature could be reduced to 80 – 85° C.
If any risk of dry running a flush should be added.
Cavitation check
NPSHa should be greater than NPSHr i.e., 3 m 4.1
m. This means that the pump would cavitate at the
90° C so we should look for a larger pump or maybe
decrease the temperature.
148
7.0
Pump
Sizing

7.5 Worked Examples – Centrifugal Pump Sizing
US units
7.5.1 Example 1
The following example in Fig. 7.5.1a shows a pump to
be sized for a typical brewery process.
The pump is required to handle Wort from the
Whirlpool to the Fermentation vessel.
Yeast
Yeast pitching
Cooling
Wort pump
Whirlpool
262 ft
9 PSI
(pressure vessel)
69
ft
Fermentation
CIP
CO2
CO2
O2
CIP
CO2
CO2
149
7.0
Pump
Sizing

by the customer.
Product/Fluid data:
Fluid to be pumped - Wort
Viscosity - 1 cP
Pumping temperature - 194° F
Performance data:
Capacity - 176 US gal/min
Discharge - via 262 ft of 4 in dia. tube,
plus a given number of
bends, valves, and a plate
heat exchanger with ∆pPHE
23 PSI. Static head in
Fermenting vessel = 69 ft.
Pressure in Fermenting
vessel = 9 PSI
Suction - 1.5 ft head, plus a given
number of bends and
valves
Site Services data:
150
7.0
Pump
Sizing

Total head
ht = Static Head in Fermentation Vessel
pt = Pressure in Fermentation Vessel
Therefore:
ht = 69 ft
∆ptube (from curve shown in 14.5) = 4.7 ft
(5.9 ft loss per 328 ft) = for 262 ft tube
- loss 4.7 ft
∆p is calculated to be 16 ft
∆pPHE is given as 23 PSI = 53 ft
hft = 4.7 + 16 + 53 ft = 73.7 ft
pt = 9 PSI = 20 ft
Ht = ht + hft + pt = 69 + 73.7 + 20 ft = 162.7 ft (70.5 PSI)
hs = Static Suction Head in Whirlpool
ps = Pressure in Whirlpool (open tank)
Therefore:
hs = 1.5 ft
hfs = Calculated to be 3 ft
ps = 0 (open tank)
Hs = hs - hfs +ps = 1.5 - 3 + 0 m = - 1.5 ft (- 0.6 PSI)
Total head H = Ht - Hs = 162.7 - (- 1.5) = 164.2 ft (71.2 PSI)
h
t
h
s
pt
ps
hfs hft
151
7.0
Pump
Sizing

NPSHa
in Whirlpool Tank
hs = Static Suction Head in Whirlpool Tank
Therefore:
Pa = 14.7 PSI (open tank) = 33.9 ft
hs = 1.5 ft
Pvp = 10 PSIA (from table 14.4a) = 23 ft
NPSHa = 33.9 + 1.5 - 3 - 23 (ft) = 9.4 ft
follows:
Pump Model - LKH-20
Impeller size - 6.50 in
Head - 164.2 ft (71.2 PSI)
Efficiency - 67.25%
NPSHr - 7.5 ft
Motor size - 15 hp
Actual pump sizing can be made using pump perfor-
mance curves or a pump selection program. The per-
formance curves are, however, not suitable if the fluid
to be pumped has physical properties (i.e., viscosity)
different from water. In this particular example both the
pump performance curves and pump selection pro-
gram can be used. The performance curve selection
procedure is more specifically described in section
7.3.1.
Cavitation check
NPSHa should be greater than NPSHr i.e. 9.4 ft 7.5
ft, i.e., no cavitation will occur.
a double mechanical seal with carbon/silicon carbide
152
7.0
Pump
Sizing

Special Note
The discharge head (ht2
) is lower when the pump starts
filling the fermenting vessel compared to the discharge
head (ht1
) when the vessel is full. The reduction of
the discharge head will result in higher flow. This will
reduce the NPSHr and can therefore lead to cavitation.
Another risk is that the larger capacity and thereby
larger power consumption can cause overloading of
the motor (see Fig. 7.5.1c).
Cavitation can be avoided by reducing the pump
speed (reducing NPSHr), i.e., by means of a frequency
converter, or by throttling the discharge line (increasing
head). The flow control method is more specifically
described in section 7.3.2.
Adjustment
In this example the pump is sized by the pump selec-
tion program which results in exact impeller diameter
of 6.50 in, so that the selected duty point is as close to
the required duty point as possible.
The pump is sized with a standard impeller diameter
if using the performance curve. In this case it may be
necessary to adjust the selected duty point by means
of flow control.
It is important to note that the selected head has a
tolerance of ± 5% due to the tolerance of the pump
curve. Consequently, there is a risk that the pump
capacity will differ from the selected. If the required
capacity is the exact value of the process, it is recom-
mended to adjust to the required duty point by means
of flow control. Flow control method is more specifical-
ly described in section 7.3.2.
1: Full vessel
2: Empty vessel
Fig. 7.5.1c Q - H charateristic when changing valves
H
ht1
ht2
2
1
Q
Q1 Q2
153
7.0
Pump
Sizing

7.5.2 Example 2
The following example in Fig. 7.5.2a shows a centrifu-
gal pump to be sized for a typical dairy process.
Pump 'A' is a Raw Milk pump in connection with a
pasteuriser. The raw milk is pumped from a Balance
Tank to a Separator via the preheating stage in the
plate heat exchanger.
Separator
P = 22 PSI
Standardised Milk
PHE
Pump ‘A’
Balance Tank
CIP
Milk out
7.0
Pump
Sizing

Product/Fluid data:
Fluid to be pumped - Raw Milk
Viscosity - 5 cP
Performance data:
Discharge - via 16 ft of horizontal 3
in dia. tube, plus a given
number of bends, valves,
er with ∆pPHE 15 PSI.
Inlet pressure for the sep-
arator = 22 PSI
Suction - 0.3 ft head, plus a given
number of bends, and
valves
Site Services data:
by the customer.
As described in 7.1 in order to correctly size any type
of pump, some essential information is required such
as Product/Fluid data, Performance data and Site
Services data.
155
7.0
Pump
Sizing

Total head
ht = Static Head to Separator
pt = Pressure in Separator
Therefore:
ht = 0 ft (no static head - only horizontal tube)
∆ptube (from curve shown in 14.5) = 0.6 ft
(4 m loss per 100 m = 0.2 m = 0.6 ft)
∆p is calculated to be 0.3 ft
∆pPHE is given as 15 PSI = 34 ft
hft = 0.6 + 0.3 + 34 ft = 34.9 ft
pt = 22 PSI = 50 ft
Ht = ht + hft +pt = 0 + 34.9 + 50 ft = 84.9 ft (36.8 PSI)
Therefore:
hs = 0.3 ft
hfs = Calculated to be 1.3 ft
ps = 0 (open tank)
Hs = hs - hfs + ps = 0.3 - 1.3 + 0 m = - 1 ft (- 0.4 PSI)
Total head H = Ht - Hs = 84.9 - (- 1) = 85.9 ft (37.2 PSI)
the total head and NPSHa (Fig. 7.5.2b). The theory,
including the different formulae regarding these
parameters is more specifically described in section
2.2.2 and 2.2.4.
h
t
h
s pt
ps
hfs hft
156
7.0
Pump
Sizing

NPSHa
in Balance Tank
Therefore:
hs = 0.3 ft
Pvp = At temperature of 41° F this is taken
as being negligible i.e., 0 PSIA = 0 ft
NPSHa = 33.9 + 0.3 - 1.3 - 0 (ft) = 32.9 ft
follows:
Pump Model - LKH-10
Head - 84.9 ft (36.8 PSI)
Efficiency - 65.4%
NPSHr - 4.6 ft
Motor size - 5.0 hp
As the fluid to be pumped has physical properties (i.e.,
viscosity) different from water, the pump performance
curves should not be used, and actual pump sizing
should be made using the pump selection program.
Cavitation check
NPSHa should be greater than NPSHr i.e., 32.9 ft 4.6
ft, i.e., no cavitation will occur.
157
7.0
Pump
Sizing

Product/Fluid data:
Fluid to be pumped - CIP return
Viscosity - 1 cP
Pumping temperature - 41° F - 194° F
Performance data:
Capacity - 132 GPM
Discharge - via 16 ft of horizontal 3
in dia. tube, plus a given
number of bends, valves,
er with ∆pPHE 15 PSI and
22 PSI over a separator
Suction - 1.6 ft static head, plus a
given number of bends
and valves all together
with a friction loss of 1.6 ft
Site Services data:
7.5.3 Example 3
A CIP return pump is to be sized for an application for
the following details given by the customer.
158
7.0
Pump
Sizing

Total head
Total Discharge head Ht = ht + hft + pt
Taken from Example 2 (same head) = 84.9 ft (36.8 PSI)
Therefore:
hs = 1.6 ft
ps = 0 (open tank)
Hs = hs - hfs + ps = 1.6 - 1.6 + 0 m = 0 ft = (0 PSI)
Total head H = Ht - Hs = 85.9 - 0 = 85.9 ft (37.2 PSI)
NPSHa
in Balance Tank
Therefore:
hs = 1.6 ft
Pvp = At temperature of 194° F (important to check
at highest temperature. Table 14.4)
0.7 bar = 23.4 ft
NPSHa = 33.9 + 1.6 - 1.6- 23.4 ft = 10.5 ft
159
7.0
Pump
Sizing

Using a sizing program we get the option of a LKH
Prime-20:
Capacity - 132 GPM
Head - 85.9 ft (37.2 PSI) - it is
Efficiency - 44.91%
NPSHr - 13.6 ft
Power absorbed - 6.3 hp
Motor size - 7.5 hp
Checking another size pump, LKH-40 the option is
the below:
Capacity - 132 GPM
Head - 85.9 ft (37.2 PSI) - it is
Efficiency - 36.15%
NPSHr - 7.9 ft
Power absorbed - 7.8 hp
Motor size - 10 hp
Cavitation check
NPSHa should be greater than NPSHr i.e., 10.5 ft
13.6 ft.
This means that the pump would cavitate at the
194° F so we should look for a larger pump or
maybe decrease the temperature.
Checking another size pump it will be necessary to
use a variable frequency drive if we would still want to
have a LKH-Prime pump. Using a sizing program we
can get the below:
Cavitation check
NPSHa should be greater than NPSHr i.e., 10.5 ft 7.9
ft.
This would work. However, the efficiency goes down
and higher power consumption so it is worth checking
if temperature could be reduced to 176 – 185° F.
faces and EPDM elastomers. If any risk of dry running
add a flush.
160
7.0
Pump
Sizing

7.6 Positive displacement Pumps
7.6.1 Slip
Slip is the fluid lost by leakage through the pump
clearances. The direction of slip will be from the high
pressure to the low pressure side of the pump i.e. from
pump outlet to pump inlet (see Fig. 7.6.1a). The amount
of slip is dependent upon several factors.
Clearance effect
Increased clearances will result in greater slip. The size
and shape of the rotor will be a factor in determining
the amount of slip.
Pressure effect
The amount of slip will increase as pressure increases
which is shown above. In Fig 7.6.1b for a given pump
speed the amount of slip can be seen as the capacity
at ‘zero’ bar less the capacity at ‘X’ bar. To overcome
this amount of slip it will be necessary to increase
the pump speed to maintain the capacity required as
shown in Fig 7.6.1c.
Fig. 7.6.1a Slip
Fig. 7.6.1b Pressure effect Fig. 7.6.1c Pressure effect
Outlet
High pressure
Inlet
Low pressure
Slip
Slip
Slip
Speed rev/min
Capacity
A = Capacity at ‘0’ bar
B = Actual capacity at ‘X’ bar
C = Slip
D = ‘0’ bar
E = ‘X’ bar
A
B
C
D
E
Speed rev/min
Capacity
A = Required capacity
B = Speed increase to
C = ‘0’ bar
D = ‘X’ bar
A
C D
maintain capacity
B
161
7.0
Pump
Sizing

Viscosity effect
The amount of slip will decrease as fluid viscosity
increases. The effect of viscosity on slip is shown in
Fig. 7.6.1d, 7.6.1e and 7.6.1f above. The pressure lines
will continue to move towards the ‘zero’ pressure line
as the viscosity increases.
Pump Speed effect
Slip is independent of pump speed. This factor must
be taken into consideration when operating pumps
at low speeds with low viscosity fluids (Fig. 7.6.1g).
For example, the amount of slip at 400 rev/min pump
speed will be the same as the amount of slip at 200
rev/min pump speed providing pressure is constant.
The pump speed required to overcome slip is known
as the ‘dead head speed’.
It is important to note that flow will be positive after
overcoming the dead head speed.
Speed rev/min
C = Required capacity
Viscosity = 1 cP
Capacity
A = ‘0’ bar
B = ‘X’ bar
C
A B
Speed rev/min
Viscosity = 10 cP
Capacity
A = ‘0’ bar
B = ‘X’ bar
C
A B
Speed rev/min
Viscosity = 50 cP
Capacity
A = ‘0’ bar
B = ‘X’ bar
C
A B
Speed rev/min
Capacity
A = 0 bar
B = 7 bar
C = Dead head speed
A B
C
Fig. 7.6.1d Viscosity effect
Fig. 7.6.1g Dead head speed
Fig. 7.6.1e Viscosity effect Fig. 7.6.1f Viscosity effect
162
7.0
Pump
Sizing

A summary of effects of different parameters on slip is
shown below (Fig. 7.6.1j):
It is worth noticing that the clearances in a circumfer-
ential piston pump like the Alfa Laval DuraCirc pump
is smaller than in a rotary lobe pump making the
DuraCirc a lot less sensitive to slip.
The Twin Screw pump such as the Alfa Laval OS will
have relatively larger clearances due to screw length
and overhang. As such this means greater slip but this
can be compensated with increased speed where the
product allows for this.
Slip
Pressure
Slip
Clearance
Increases with Pressure Increases with Clearances Decreases with Viscosity
Slip
Viscosity
Fig. 7.6.1j
163
7.0
Pump
Sizing

Product/Fluid data:
Fluid to be pumped - Vegetable Oil
Viscosity - 100 cSt
Pumping temperature - 30° C (86° F)
Performance data:
Capacity - 3.6 m3
/h (15.8 US gal/min)
Total Pressure - 8 bar (116 PSIG)
7.6.2 Initial Suction Line Sizing
In general terms it is common to find the recommen-
dation for the inlet pipe size to be the same diameter
as the pump inlet connection.
For guidance purposes only on high viscosity duties,
the suction line can be initially sized using the initial
suction line sizing curve (see section 14.9) where the
relationship between viscosity and flow rate provides
an indication of pipe sizing.
For example, for a flow rate of 10 m3
/h on a fluid with
viscosity 900 cSt, a pump with 40 mm (1.5 in) diameter
suction line would be initially selected.
It is important to note this is only an approximate guide
and care should be taken not to exceed the pump’s
viscosity/speed limit.
7.6.3 Performance Curve
Alfa Laval positive displacement pumps can be sized
from published performance curves or a pump selec-
tion program. Due to pump head clearances described
in section 8.2.2, different performance curves are used
for SRU pumps for the various temperature ratings for
rotors i.e., 70° C (158° F), 130° C (266° F) and 200° C
(392° F). The SX pump range has only 150° C (302° F)
and the Optilobe pump range has only 130° C (266° F)
temperature ratings. The Circumferential Piston Pump,
DuraCirc, has 150° C (302° F) temperature rating.
For the Alfa Laval OS Twin Screw pump curves has not
been published and should therefore always be select-
ed using a pump selection program. This is to avoid
any issues when several duties have to be considered.
If access to Anytime a selection guideline is avaiable
here for the OS pump.
How to use the Performance Curve
There are two kinds of performance curves.
For the first Fig. 7.6.3a.
The performance curve consists of
four different curves:
• Capacity as a function of speed, related to pres-
sure and viscosity
• Power as a function of speed, related to pressure
and viscosity of 1 cSt
(see table 14.3.10 for viscosity conversion)
• Power as a function of viscosity greater than 1 cSt
• Speed as a function of viscosity
The curves are based on water at 20° C (68° F) but
are shown with calculated viscosity correction data.
Example shown refers to the SRU pump range, but the
same sizing procedure is also used for the SX pump
range.
Example
The optimum is to size the smallest pump
possible as hydraulic conditions dictate.
However other factors such as fluid behaviour,
solids etc. should be considered.
164
7.0
Pump
Sizing

165
7.0
Pump
Sizing

A
B
C
D
E
F
G
Rotors
-
St.
Stl.
Trilobe
10
Bar
(145
PSI)
70°
(158
°F)
A
=
0.5
bar
B
=
1
bar
C
=
2
bar
D
=
4
bar
E
=
6
bar
F
=
8
bar
G
=
10
bar
Viscosity
(cSt)
10
1
100
1,000
10,000
100,000
Power
at
1
cSt
Flow
A
=
0.5
bar
B
=
1
bar
C
=
2
bar
D
=
4
bar
E
=
6
bar
F
=
8
bar
G
=
10
bar
Total
Power
=
(PV
x
rpm)/10,000
+
kW
(1
cSt)
Curves
are
representative.
Specific
pumps
may
vary
in
performance
due
to
manufacture,
pumped
fluids.
6
7
Typical
Performance
curve
SRU2/013/with
mechanical
seal
5
4
2
1
0
3
Flow
m
3
/hr
Speed
rpm
0
100
200
300
400
500
600
700
800
900
1,000
Max.
Viscosity
(cSt)
x
100
(at
0
bar)
Port
Diameter
22.2
mm
350
172
110
78
58
43
32
23
16
9
1
10
P
r
e
s
s
u
r
e
B
a
r
100
1,000
(cSt)
PV
Factor
5
10
15
0
Speed
rpm
0
Max
speed
=
1,000
rpm
100
200
300
400
500
600
700
800
900
1,000
Power
kW
0
1
2
3
A
B
C
D
E
F
G
Bar
Fig. 7.6.3a SRU2/013/LS curves

Typically curves are used in conjunction with equation as
follows:
Total Required Power (kW) =
Pv x Pump speed (rev/min) + Hydraulic power at 1 cSt (kW)
10000
Where: Pv = Power/Viscosity Factor
From example
• At speed 600 rev/min and 8 bar the hydraulic power at
1 cSt is 1.3 kW
• At viscosity 100 cSt the Pv factor is 1.0
Pv x Pump speed (rev/min) + Hydraulic power at 1 cSt (kW)
10000
= 1.0 x 600 + 1.3
10000
= 1.36 kW (1.82 hp)
Step 1 – Find Appropriate Curve
Locate a curve for the required pump model that
covers the performance data. Due to the large number
of curves available it is not practical to include all
performance curves in this handbook. Curves can be
obtained from the pump supplier, or downloaded from
our Anytime program if you have access. However, the
sizing process would be as follows:
From the initial suction line sizing curve (see section
14.9), a pump with a size 25 mm (1 in) inlet connection
would be required. Although the smallest pump
models SRU1/005 and SRU1/008 have 25 mm (1 in)
pump inlet connections, the flow rate required would
exceed the pumps speed limit on the performance
curve. For this particular example, we therefore need
to select a performance curve for the pump model
SRU2/013/LS with 70° C (158° F) rotor clearances, as
shown in Fig. 7.6.3a, being the next appropriate pump
size.
Step 2 – Find Viscosity and Pressure
Begin with viscosity and find the intersection point
with duty pressure.
From example – 100 cSt and 8 bar (115 PSIG).
Step 3 – Find Flow Rate
Move diagonally downward and find intersection
with required flow rate.
From example – 3.6 m3
/h (15.8 US gal/min).
Step 4 – Find Speed
Move vertically downward to determine necessary
pump speed.
From example – 600 rev/min.
Step 5 – Viscosity/Port Size Check
Move vertically downward and check that maximum
viscosity rating has not been exceeded against rele-
vant inlet size.
From example – maximum viscosity rating 4300 cSt.
Step 6 – Find Power
The power required by a pump is the summation of the
hydraulic power and various losses that occur in the
pump and pumping system. Viscosity has a marked
effect on pump energy losses. The losses being due
to the energy required in effecting viscous shear in the
pump clearances. Viscous power is the power loss
due to viscous fluid friction within the pump (Pv factor).
It should be noted, this is the power needed at the
pump shaft and the appropriate motor power must be
selected, which in this instance would be 1.5 kW being
the nearest motor output power above the required
power.
167
7.0
Pump
Sizing

0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Metres
Water
Speed rev/min
A = 100,000 cSt
B = 60,000 cSt
C = 30,000 cSt
D = 20,000 cSt
E = 10,000 cSt
F = 5,000 cSt
G = 2,500 cSt
H = 1,000 cSt
I = 1 cSt
Feet
Water
0
0 100 200 300 400 500 600 700 800 900 1000
5
10
15
14.4 4.4
20
25
30
35
40
45
50
A B
C D E F
G
H
I
Fig. 7.6.3b SRU2 typical NPSHr curve based on water
168
7.0
Pump
Sizing

Step 7 – Find NPSHr
NPSHr can be found by looking at the appropriate
NPSH pump curve, which is a function of speed and
expressed in metres water column (mwc) or feet (ft).
From example – at speed 600 rev/min and 100 cSt the
NPSHr is 4.4 mwc (14.4 ft) (Fig. 7.6.3b).
169
7.0
Pump
Sizing

For the newer curves used for Optilobe and DuraCirc
(Fig. 7.6.3c).
The performance curve consists of five
different curves
• Capacity as a function of speed, related to pres-
sure at 1 cPs
• Viscosity correction factor in relation to viscosity
pressure and speed
• Power as a function of speed, related to pressure
and viscosity of 1 cPs
(see table 14.3.10 for viscosity conversion)
• Power correction factor in relation to viscosity
• Speed as a function of viscosity
The curves are based on water at 20° C (68° F) but
are shown with calculated viscosity correction data.
Different curves exists for SI units and American units.
Examples shown refers to the DuraCirc pump range,
but the same sizing procedure is also used for the
Optilobe pump range.
7.0
Pump
Sizing

60
50
40
30
20
10
0
Speed
rpm
Flow
at
1
cPs
Curves
are
representative.
Specific
pumps
may
vary
in
performance
due
to
manufacture,
pumped
fluids.
Power
at
1
cPs
Viscosity
Corrected
Power
=
(PV
x
rpm)/10,000
+
kW
(1
cPs)
Flow
m
3
/hr
0
100
200
300
400
500
600
700
800
900
1000
Speed
rpm
Viscosity
cPs
Viscosity
cPs
PV
Factor
Power
Viscosity
Correction
Viscosity
Corrected
DHS
rpm
cPs
Flow
-
Viscosity
Corretion
Power
kW
0
0
2
4
6
8
10
12
14
16
100
200
300
400
500
600
700
800
900
1000
Max.
Viscosity
(cPs)
x
100
at
0
bar
Port
Diameter
80
mm
100
200
300
400
500
600
700
800
900
1000
1000
100
10
1
1000
10,000
100,000
100
10
1
0
100
200
300
400
5871
2904
1912
1406
1092
879
719
597
498
415
A
=
0
bar
B
=
0.5
bar
C
=
1
bar
D
=
2
bar
E
=
3
bar
F
=
4
bar
G
=
5
bar
H
=
6
bar
I
=
7
bar
J
=
8
bar
A
=
8
bar
B
=
7
bar
C
=
6
bar
D
=
5
bar
E
=
4
bar
F
=
3
bar
G
=
2
bar
H
=
1
bar
I
=
0.5
bar
A
=
8
bar
B
=
7
bar
C
=
6
bar
D
=
5
bar
E
=
4
bar
F
=
3
bar
G
=
2
bar
H
=
1
bar
I
=
0.5
bar
A
B
C
D
E
F
G
H
I
J
OptiLobe
43
Typical
Performance
curve
based
on
water,
with
viscosity
correction
curves
With
stainless
steel
130º
C
TriLobe
rotors
and
mechanical
seal
A
B
C
D
E
F
G
H
I
A
B
C
D
E
F
G
H
I
100
10
20
30
40
50
60
70
80
90
0
Fig. 7.6.3c OptiLobe 43 Typical performance curve based on water, with viscosity correction curves
With stainless steel 130º C TriLobe rotors and mechanical seal
171
7.0
Pump
Sizing

Example SI units
Duty:
Viscosity: 10 cPs
Pressure: 10 bar
Flow rate: 4 m3
/hr
Step 1 – to calculate speed:
• Using the Flow Viscosity Correction curve (Fig.
7.6.3d), draw a straight line up from the 10 cps
viscosity point on the x-axis until it intersects the
(10 bar) pressure line
• Draw a line across until it intersects the y-axis and
read off the viscosity corrected dead head speed
(DHS), in this case 165 rpm
Flow Viscosity Correction
Viscosity
Correction
DHS
rmp
1 10 100
100
200
300
400
500
165
0
A = 20 bar
B = 17 bar
C = 15 bar
D = 12 bar
E = 10 bar
F = 5 bar
G = 3 bar
H = 1 bar
I = 0.5 bar
1000
Viscosity cPs
A
B
C
D
E
F
G
H
I
Fig. 7.6.3d
172
7.0
Pump
Sizing

• Using the Flow at 1 cPs curve (Fig. 7.6.3e) starting
at the viscosity corrected DHS speed value of 165
rpm, draw a line parallel to the pressure lines
• At the desired flow rate of 4 m3
/hr, draw a line
parallel to the x-axis, until it intersects the line
drawn described below
• Then draw a line parallel to the y-axis down
until it intersects the x-axis and read off the
corresponding speed
• This speed (of 460 rpm) is the resulting duty
speed
Flow at 1 cPs
Curves are representative.
Specific pumps may vary
in perdoemance due to
manufacture, pumped fluids
m
3
/hr
Speed rpm
12
10
8
6
4
2
0
165 460
A = 0 bar
B = 0.5 bar
C = 1 bar
D = 3 bar
F = 5 bar
G = 10 bar
H = 12 bar
I = 15 bar
J = 17 bar
K = 20 bar
0 100 200 300 400 500 600 700 800
A
B
C
D
F
G
H
I
J
K
Fig. 7.6.3e
173
7.0
Pump
Sizing

Step 3 – to calculate power:
• Using the Power at 1 cPs Curve (Fig. 7.6.3f),
starting at the duty speed of 460 rpm, draw a line
parallel to the y-axis, until it intersects the duty
pressure line (10 bar)
• Draw a line parallel to the x-axis, until it insects the
y-axis and read off the power value
• This value is the power absorbed requirement at
1 cPs (2.0 kW)
Power at 1 cPs
Viscosity Corrected Power = (PV x rmp)/10,000 + Power (1 cPs)
kW
Speed rpm
460
0 100
A = 20 bar
B = 17 bar
C = 15 bar
D = 12 bar
E = 10 bar
F = 5 bar
G = 3 bar
H = 1 bar
I = 0.5 bar
200 300 400 500 600 700 800
7
6
5
4
3
2
1
0
A
B
C
D
E
F
G
H
I
Fig. 7.6.3f
174
7.0
Pump
Sizing

• Using the Power Viscosity Correction curve
(Fig. 7.6.3g), starting at the duty viscosity of 10 cPs,
draw a line parallel to the y-axis, until it intersects
the curve
y-axis and read off the PV value (0.7)
• Using the Viscosity Corrected Power formula
shown, calculate total power absorbed require-
ment:
Total power requirement
= (0.7 x 460) + 2.0 = 2.03 kW
10000
Power Viscosity Correction
0.7
1 10 100 1,000 10,000 100,000
PV
Factor
Viscosity cPs
30
25
20
15
10
5
0
Fig. 7.6.3g
175
7.0
Pump
Sizing

Example US units
Duty:
Viscosity: 10 cPs
Pressure: 130 PSI
Flow rate: 60 US GPM
• Using the Flow-Viscosity Correction curve
(Fig. 7.6.3h), draw a straight line up from the 10 cPs
viscosity point on the x-axis until it intersects the
(130 PSI) pressure line
• Draw a line across until it intersects the y-axis and
read off the viscosity corrected dead head speed
(DHS), in this case 115 rpm
Flow - Viscosity Correction
Viscosity
Correction
DHS
rmp
1 10 100
115
100
200
300
0
A = 232.1 PSI
B = 188.5 PSI
C = 159.5 PSI
D = 130.5 PSI
E = 101.5 PSI
F = 72.5 PSI
G = 43.5 PSI
H = 14.5 PSI
I = 7.3 PSI
1000
Viscosity cPs
A
B
C
D
E
F
G
H
I
Fig. 7.6.3h
176
7.0
Pump
Sizing

• Using the Flow at 1 cps curve (Fig. 7.6.3i), starting
at the viscosity corrected DHS speed value of 115
rpm, draw a line parallel to the pressure lines
• At the desired flow rate of 60 US GPM, draw a
line parallel to the x-axis, until it intersects the line
drawn described above
• Then draw a line parallel to the y-axis down until it
intersects the x-axis and read off the correspond-
ing speed
• This speed (of 355 rpm) is the resulting duty speed
Flow at 1 cPs
Curves are representative.
Specific pumps may vary
in perdoemance due to
manufacture, pumped fluids
US
GPM
Speed rpm
200
180
160
140
120
100
80
60
40
20
0
115 355
A = 0 PSI
B = 7.3 PSI
C = 1.5 PSI
D = 43.5 PSI
F = 72.5 PSI
G = 101.5 PSI
H = 130.5 PSI
I = 159.5 PSI
J = 188.5 PSI
K = 232.1 PSI
0 100 200 300 400 500 600 700 800
A
B
C
D
F
G
H
I
J
K
Fig. 7.6.3i
177
7.0
Pump
Sizing

• Using the Power at 1 cPs curve (Fig. 7.6.3j), starting
at the duty speed of 355 rpm, draw a line parallel
to the y-axis, until it intersects the duty pressure
line (130 PSI)
y-axis and read off the power value
• This value is the power absorbed requirement at 1
cPs (8 hp)
Power at 1 cPs
Viscosity Corrected Power = (PV x rmp)/10,000 + Power (1 cPs)
HP
Speed rpm
460
0 100
A = 232.1 PSI
B = 188.5 PSI
C = 159.5 PSI
D = 130.5 PSI
E = 101.5 PSI
F = 72.5 PSI
G = 43.5 PSI
H = 14.5 PSI
I = 7.3 PSI
200 300 355 400 500 600 700 800
8
35
30
25
20
15
10
5
0
A
B
C
D
E
F
G
H
I
Fig. 7.6.3j
178
7.0
Pump
Sizing

• Using the Power Viscosity Correction curve
(Fig. 7.6.3k), starting at the duty viscosity of 10 cPs,
draw a line parallel to the y-axis, until it intersects
the curve
• Draw a line parallel to the x-axis, until it intersects
the y-axis and read off the PV value (3)
• Using the Viscosity Corrected Power formula
shown, calculate total power absorbed require-
ment:
Total power requirement
= (3 x 355) + 8.0 = 8.1 hp
10000
Power Viscosity Correction
3
1 10 100 1,000 10,000 100,000
PV
Factor
Viscosity cPs
120
100
80
60
40
20
0
Fig. 7.6.3k
179
7.0
Pump
Sizing

(Stainless Steel)
These rotors, described in section 8.2.1, are available
for SRU pumps and mainly used on high viscosity
products containing solids where the pumps volumet-
ric efficiency is high. When pumping such products
optimum performance is obtained by using large slow
running pumps.
Applications on water like viscosity fluids would result
in slightly decreased efficiency over stainless steel
Tri-lobe rotors. For this reason specific performance
curves are available for Bi-lobe SS rotors where dead
head speed is slightly higher than for Tri-lobes. Due
to pump head clearances described in 8.2.2, different
performance curves are used for the various temper-
ature ratings of rotors i.e., 70° C (158° F), 130° C (266°
F) and 200° C (392° F). The use of performance curves
is as described in section 7.6.3.
NPSHr is slightly reduced when using Bi-lobe rotors.
(Non Galling Alloy)
These rotors, described in section 8.2.1, have very
small clearances resulting in increased volumetric
efficiency over non Galling rotors when used on fluids
with viscosities up to 50 cP. Pump sizing is achieved
by referring to published performance curves or a
pump selection program. Due to pump head clearanc-
es described in 8.2.2, different performance curves
are used for the various temperature ratings of rotors
i.e., 70° C (158° F), 130° C (266° F) and 200° C (392°
F). The use of performance curves is as described in
section 7.6.3.
180
7.0
Pump
Sizing

Pump Model Percentage Increase Required on Stainless Steel
Tri-lobe Rotor Dead Head Speed
SRU range Electropolishing only Mechanical and Electropolishing
1/005 17.0 60.0
1/008 15.1 55.0
2/013 10.8 45.8
2/018 8.5 38.0
3/027 6.7 32.7
3/038 5.5 28.5
4/055 4.6 24.8
4/079 3.8 21.0
5/116 2.9 18.0
5/168 2.4 15.5
6/260 2.0 12.8
6/353 1.7 11.4
Pump Model Percentage Increase Required on Multi-lobe
Rotor Dead Head Speed
SX range Electropolishing only Mechanical and Electropolishing
1/005 12.0 60.0
1/007 9.3 47.6
2/013 8.3 40.9
2/018 7.7 38.4
3/027 6.9 34.0
3/035 6.2 31.3
4/046 5.6 28.6
4/063 5.0 25.5
5/082 4.5 22.8
5/116 4.0 19.3
6/140 3.5 17.0
6/190 2.9 14.0
7/250 2.2 11.3
7/380 1.3 6.8
Table 7.6.6a
Table 7.6.6b
7.6.6 Pumps with Electropolished
Surface Finish
Pump performance will be affected by electropolish
surface finish to the pump head internals. For sizing
purposes a percentage increase on the ‘dead head
speed’ (see tables below) should be applied to the
performance curve for stainless steel Tri-lobe rotors
and interpolated accordingly.
181
7.0
Pump
Sizing

Solids form
- Optimum Conditions
Spherical
Solids physical properties i.e.,
hardness, resilience, shear,
strength
- Soft, yet possess resilience and
shear strength
Solids surface finish - Smooth
Fluid/solids proportion - Proportion of solids to fluid is small
Relationship of fluid/solid SG - Equal
Flow velocity (pump speed) - Maintained such that solids in
suspension are not damaged
Rotor form - Bi-lobe (If SRU)
Port size - Large as possible
7.6.7 Guidelines for Solids Handling
The following criteria should be considered when
deciding the pump's ability to handle large solids in
suspension.
182
7.0
Pump
Sizing

OptiLobe Model Tri-lobe Rotors SRU Model Bi-lobe Rotors Tri-lobe Rotors
mm in mm in mm in
12 6 0.24 SRU1/005 8 0.31 6 0.24
13 6 0.24 SRU1/008 8 0.31 6 0.24
22 8 0.31 SRU2/013 8 0.31 6 0.24
23 8 0.31 SRU2/018 13 0.51 9 0.34
32 10 0.39 SRU3/027 13 0.51 9 0.34
33 10 0.39 SRU3/038 16 0.63 11 0.44
42 12 0.47 SRU4/055 16 0.63 11 0.44
43 12 0.47 SRU4/079 22 0.88 15 0.59
52 16 0.63 SRU5/116 22 0.88 15 0.59
53 16 0.63 SRU5/168 27 1.06 18 0.72
SRU6/260 27 1.06 18 0.72
SRU6/353 37 1.47 24 0.94
SX Model Multi-Lobe Rotors
mm in
SX1/005 7 0.28
SX1/007 7 0.28
SX2/013 10 0.39
SX2/018 10 0.39
SX3/027 13 0.51
SX3/035 13 0.51
SX4/046 16 0.63
SX4/063 16 0.63
SX5/082 19 0.75
SX5/115 19 0.75
SX6/140 25 0.98
SX6/190 25 0.98
SX7/250 28 1.1
SX7/380 28 1.1
Table 7.6.7a
Tables below show the maximum spherical solids
size that can be satisfactory handled without product
degradation, providing the optimum conditions are
met. For non-optimum conditions these should be
referred to Alfa Laval.
183
7.0
Pump
Sizing

Model Max. Solids
mm in
DuraCirc 32 8 0.3
DuraCirc 33 8 0.3
DuraCirc 34 13 0.5
DuraCirc 42 13 0.5
DuraCirc 43 13 0.5
DuraCirc 52 17 0.7
DuraCirc 53 21 0.8
DuraCirc 54 25 1.0
DuraCirc 62 25 1.0
DuraCirc 63 34 1.3
DuraCirc 72 34 1.3
DuraCirc 73 51 2.0
DuraCirc 74 51 2.0
Maximum Solids Handling mm (inch)
OS1x OS2x OS3x OS4x
mm in mm in mm in mm in
OS12 6 0.24 OS22 12 0.47 OS32 16 0.63 OS42 21 0.82
OS14 11 0.43 OS24 16 0.63 OS34 21 0.82 OS44 29 1.14
OS16 17 0.67 OS26 24 0.94 OS36 32 1.26 OS46 43 1.69
OS27 15 0.59 OS37 20 0.78
OS28 32 1.26 OS38 42 1.65
Table 7.6.7b Solid handling DuraCirc pump
Table 7.6.7C Solid handling OS Twin Screw Pump
The OS Twin Screw pump can handle up to 43 mm
(1.69) solids. The higher the screw pitch (represented
by the last number in the model number), the larger the
solid size. So an OS 36 can handle larger solids than
the OS 34. Max. solid size should be entered in the
selection program in order to get the right size pump.
184
7.0
Pump
Sizing

7.6.8 Guidelines for Pumping Shear Sensitive
Media
Special attention needs to be made to pumping shear
sensitive media such as yeast and yoghurt where the
cell structure needs to remain intact. Excess pump
speed can irreversibly damage the cell structure.
Therefore pump speeds need to be kept relatively low,
in the range of 100 to 400 rev/min dependent upon
the fluid being pumped, technology type, pump size/
model and rotor form. For these types of applications
refer to Alfa Laval.
185
7.0
Pump
Sizing

7.7 Worked Examples – Positive Displacement Pump Sizing
Metric units
The following examples show two different posi-
tive displacement pumps to be sized for a typical
sugar process and one pump to be sized for juice
concentrate.
Pump 1
A low viscosity example handling sugar syrup
Pump 2
A high viscosity example handling massecuite x
Pump 3
A double duty example handling juice concentrate
and CIP
of pump, information is required such as Product/Fluid
data, Performance data and Site Services data.
7.0
Pump
Sizing

Product/Fluid data:
Fluid to be pumped - Sugar Syrup
Viscosity in pump - 80 cP
SG - 1.29
CIP temperature - 95° C
by the customer.
Performance data:
Capacity - 9 m3
/h
Discharge - via 10 m of 51 mm dia.
tube, plus 1 bend 90°
and 1 butterfly valve.
Static Head in Vessel =
8 m.
Pressure in Vessel = 1 bar
Suction - via 3 m of 51 mm dia.
tube, plus 2 bends 90°
and 1 non-return valve.
Static Head in Tank = 2 m
Site Services data:
Pump 1 – Thin Sugar Syrup pump
3 m
1 bar
1
m
6
m
2
m
1 m
1
m
1 m
Feed Tank
8
m
Fig. 7.7a Pump 1 – example
187
7.0
Pump
Sizing

the total head and NPSHa (Fig. 7.7b). The theory,
including the different formulae regarding these
parameters is more specifically described in section
2.2.2 and 2.2.4.
Total head
Total Discharge head Ht = ht + hft + pt Where:
ht = Static Head in Pressurised Vessel
pt = Pressure in Vessel
Therefore:
ht = 8 m x (SG = 1.29) = 10.3 m
(calculated below)
pt = 1 bar / (SG = 1.29) x 10 = 12.9 m
Fig. 7.7b Typical suction / Discharge Head set-up
h
t
h
s pt
ps
hfs hft
188
7.0
Pump
Sizing

To ascertain hft the flow characteristic and equivalent line length must be determined as follows:
Flow Characteristic
Reynolds number Re = D x V x p
µ
Where:
p = Density (kg/m3
)
D2
Where:
Q = Capacity (m3
/h)
= 9 x 353.6
512
= 1.22 m/s
Density p = 1290 derived from SG value 1.29 (see section 2.1.5)
Therefore Re = D x V x p
µ
= 51 x 1.22 x 1290
80
= 1003
As Re is less than 2300, flow will be laminar so our calculations can continue for laminar flow.
189
7.0
Pump
Sizing

The Miller equation is now used to determine friction loss as follows:
Pf = 5 x SG x fD x L x V2
(bar)
D
Where:
Pf = Pressure Loss due to Friction (hft)
fD = Friction Factor
L = Tube Length (m)
= 5 x 1.29 x 0.064 x 12 x 1.222
(bar)
51
= 0.14 bar = 1.4 m
Ht = ht + hft + pt = 10.3 + 1.4 + 12.9 m = 24.6 m (2.46 bar)
hs = Static Suction Head in Tank
ps = Pressure in Tank (open tank)
For this example:
hs = 2 m x (SG = 1.29) = 2.6 m
hfs = Calculated below
ps = 0 (open tank)
Equivalent Line Length – Discharge Side
The equivalent lengths of straight tube for bends
and valves are taken from table 14.7.1a. Since flow
is laminar, the viscosity correction factor is 1.0 (see
section 2.2.2).
Straight Tube Length = 3 + 6 + 1 = 10 m
1 bend 90° = 1 x 1 x 1.0 (corr. factor) = 1 m
1 butterfly valve = 1 x 1 x 1.0 (corr. factor) = 1 m
Total equivalent length = 12 m
Also as flow is laminar the friction factor fD = 64
Re
= 64
1003
= 0.064
190
7.0
Pump
Sizing

(bar)
D
Where:
L = Tube Length (m)
= 5 x 1.29 x 0.064 x 1.7 x 1.222
(bar)
51
= 0.2 bar = 2 m
Hs = hs + hfs +ps = 2.6 - 2 + 0 m = 0.6 m (0.06 bar)
Total Head H = Ht - Hs = 24.6 – 0.6 = 24 m ∆p 24 m (2.4 bar)
Straight Tube Length = 1 + 1 + 1 = 3 m
2 bends 90° = 2 x 1 x 1 (corr. factor) = 2 m
1 non-return valve = 1 x 12 x 1 (corr. factor) = 12 m
Re
= 64
1003
= 0.064
Equivalent Line Length – Suction Side
The equivalent lengths of straight tube for bends and
valves are taken from table 14.7.1. Since flow is laminar,
the viscosity correction factor is 1.0 (see section 2.2.2).
191
7.0
Pump
Sizing

NPSHa
Pa = Pressure Absolute above Fluid Level in Tank
Therefore:
Pa = 1 bar (open tank) (/1.29 x 10 ) = 7.75 m
hs = 2.6 m
Pvp = At temperature of 15° C this is taken as being
negligible i.e., 0 bar a = 0 m
NPSHa = Pa + hs
- hfs
- Pvp = 7.75 + 2.6 – 2 – 0 m = 8.35 m
Actual pump sizing can be made using pump
performance curves or a pump selection program.
The performance curve selection procedure is more
specifically described in section 7.6.3.
14.9), a pump with a size 40 mm inlet connection
would be required. As the duty is below 8 bar, and
no special seal or options are needed – the Optilobe
would be the first pump to check. As the sugar syrup
can be quite abrasive, the pump should not run much
faster than 450 rpm. Using a sizing program this gives
the below OptiLobe:
Pump Model - OptiLobe 33
Connection size - 50 mm
Speed - 417 rev/min
NPSHr - 2.1 m
Absorbed power - 1.1 kW
Cavitation check
8.35 m 2.1 m.
Power calculation
The power requirement is mentioned in AnyTime but it
is also possible to manually calculate as per below.
Pv x Pump Speed (rev/min) + Power at 1 cSt (kW)
10000
Where: Pv = Power/viscosity Factor
From example
• At speed 417 rev/min and total head 2.4 bar, the
power at 1 cSt is 0.9 kW
• At viscosity 80 cP (62 cSt) the Pv factor is 3
Pv x Pump speed (rev/min) + Power at 1 cSt (kW)
10000
= 3 x 417 + 0.9
10000
= 1.03 kW
192
7.0
Pump
Sizing

Pump Model - DuraCirc 52
Speed - 401 rev/min
NPSHr - 0.7 m
It should be noted that this is the power needed at the
pump shaft, and the appropriate motor power must be
selected, which in this instance would be 1.5 kW being
power.
Since the viscosity is relatively low an alternative to
this could be the DuraCirc pump, which is efficient at
lower viscosity. Using the same data as above this can
be selected either in a selection program or by means
of the curves. Using a selection program the following
pump is selected
The absorbed power is very close to that of the
Optilobe pump and as the Optilobe will be the less
expensive technology it would be best to go with this.
The recommended type of shaft seal based upon Alfa
a single flushed mechanical seal with silicon carbide /
silicon carbide faces and EPDM or FPM elastomers.
• Hard silicon carbide seal faces due to the abrasive
nature of sugar syrup
• Flushed version to prevent the sugar syrup from
crystallising within the seal area
• EPDM or FPM elastomers for compatibility of both
sugar syrup and CIP media
193
7.0
Pump
Sizing

Pump 2 – Massecuite pump
Product/Fluid data:
Fluid to be pumped - Massecuite
Viscosity in pump - 25,000 cP
SG - 1.35
by the customer.
Performance data:
Capacity - 10 m3
/h
Discharge - via 40 m of 76 mm dia.
tube, plus 2 bends 45°
and 1 butterfly valve.
Static head in tank = 20 m
Suction - via 1 m of 101.6 mm dia.
tube, plus 1 bend 90° and
1 butterfly valve.
Static head in tank = 2 m
Site Services data:
20
m
2
m
1
m
4
0
m
Fig. 7.7c Pump 2 - example
194
7.0
Pump
Sizing

Total head
Therefore:
ht = 20 m x (SG = 1.35) = 27 m
(calculated below)
pt = 0 bar (open tank) = 0 m
Flow Characteristic
µ
Where:
p = Density (kg/m3
)
D2
Where:
Q = Capacity (m3
/h)
= 10 x 353.6
762
= 0.61 m/s
Density p = 1350 derived from SG value 1.35 (see section 2.1.5)
µ
= 76 x 0.61 x 1350
25,000
= 2.5
As Re is less than 2300, flow will be laminar.
Fig. 7.7d
h
t
h
s
pt
ps
hfs hft
195
7.0
Pump
Sizing

valves are taken from table 14.7.1a. Since flow is lami-
nar, the viscosity correction factor is 0.25 (see section
2.2.2).
(bar)
D
Where:
L = Tube Length (m)
= 5 x 1.35 x 25.6 x 41 x 0.612
(bar)
76
= 34.7 bar = 347 m
Ht = ht + hft + pt = = 27 + 347 + 0 m = 374 m (37.4 bar)
Therefore:
hs = 2 m x (SG = 1.35) = 2.7 m
hfs = Calculated on the next page
ps = 0 (open tank)
Straight Tube Length = 40 m
2 bends 45° = 2 x 1 x 0.25 (corr. factor) = 0.5 m
1 butterfly valve = 1 x 2 x 0.25 (corr. factor) = 0.5 m
Re
= 64
2.5
= 25.6
196
7.0
Pump
Sizing

To ascertain hfs the flow characteristic and equivalent line length must be determined as follows:
Flow Characteristic
µ
Where:
p = Density (kg/m3
)
D2
Where:
Q = Capacity (m3
/h)
= 9 x 353.6
101.62
= 0.34 m/s
Density p = 1350 derived from SG value 1.35 (see 2.1.5)
µ
= 101.6 x 0.34 x 1350
25000
= 1.9
197
7.0
Pump
Sizing

is laminar, the viscosity correction factor is 0.25
(bar)
D
Where:
Pf = Pressure Loss due to Friction (hfs)
L = Tube Length (m)
= 5 x 1.35 x 33.68 x 2 x 0.342
(bar)
101.6
= 0.52 bar = 5.2 m
Hs = hs + hfs + ps = 2.7 - 5.2 + 0 m = -2.5 m
Total Head H = Ht - Hs = 374 - (-2.5) = 376.5 m ∆p 377 m (37.7 bar)
Straight Tube Length = 1 m
1 bend 90° = 1 x 2 x 0.25 (corr. factor) = 0.5 m
1 butterfly valve = 1 x 2 x 0.25 (corr. factor) = 0.5 m
Re
= 64
1.9
= 33.68
198
7.0
Pump
Sizing

Using the Miller equation to determine friction loss as follows:
(bar)
D
Where:
L = Tube Length (m)
= 5 x 1.35 x 33.68 x 41 x 0.342
(bar)
101.6
= 10.6 bar = 106 m
Now Ht = ht + hft + pt = 27 + 106 + 0 m = 133 m (13.3 bar)
Now Total Head H = Ht - Hs = 133 - (-2.5) = 135.5 m ∆p 136 m (13.6 bar)
Because of the high total head the only pump which
would be able to handle this would be the DuraCirc.
Through the selection program the below is found.
Speed - 87 rev/min
NPSHr - 0.7 m
It could however be an idea to consider reducing the
head so a smaller pump can be suitably sized, consid-
eration could be given to any or a combination of the
following parameters:
• Reduce capacity
• Increase tube diameter
• Increase pumping temperature to reduce viscosity
Assuming the capacity is a definite requirement and
the pumping temperature cannot be increased the
customer could increase the discharge tube diameter
i.e., from 76 mm to 101.6 mm.
The total head calculations are reworked, and for this
particular example the fluid velocity (V) and friction
factor (fD) have already been established for 101.6 mm
diameter tube. Also note, by referring to the equivalent
tube length table 14.7.1a the values for bends 45° and
butterfly valves remain unchanged.
199
7.0
Pump
Sizing

NPSHa
Pa = Pressure Absolute above Fluid Level in Tank
For this example:
Pa = 1 bar (open tank) = (1/1.35 x 10) = 7.4 m
hs = 2.7 m
Pvp = At temperature of 65° C this is taken
as being negligible i.e., 0 bar a = 0 m
NPSHa = Pa + hs - hfs - Pvp = 7.4 + 2.7 - 5.2 - 0 m = 4.9 m
With the new head an SRU pump or a smaller
DuraCirc circumferential piston pump could be an
option and using a pump selection program using
stainless steel Tri-lobe rotors with 130° C rotor
clearances would be as follows:
Pump Model - SRU5/168/LD
Connection size - 100 mm (enlarged port)
Speed - 100 rev/min
NPSHr - 2.3 m
Speed - 116 rev/min
NPSHr - 1.1 m
Note that by increasing the pipe size the energy
consumption is reduced from 12.2 to 5.2 kW.
Cavitation check
4.9 m 2.3 m/1.1 m
Viscosity/Port Size check
The viscosity of 25000 cP at speed 100 rev/min is well
within the pump’s maximum rated figures.
pump shaft, and for a fixed speed drive the appro-
priate motor power must be selected, which in this
instance would be 5.5 kW being the nearest motor
output power above the required power.
As the SRU will be the least expensive technology and
has the 100 mm inlet port option this would be best to
go with.
a single flushed seal with SiC/SiC seal faces and FPM
or EPDM elastomers.
200
7.0
Pump
Sizing

It is important to notice that in the above we have had
information about the in-pump viscosity. There can
be a large difference between the viscosity at rest
and the in-pump viscosity. In our selection system we
have information about the typical in-pump viscosity
for a variety of products. If in doubt about a product,
it could be worth getting it tested in order to get the
correct viscosity.
Pump speed (rev/min) n = Q x 100
q x ηv x 60
Where:
Q = Capacity (m3
/h)
/100 rev)
= 10 x 100
0.168 x 0.99 x 60
= 100 rev/min
Alternative Pump Sizing Guide Using
Volumetric Efficiency Calculation
Referring to the initial suction line sizing curve shown in
14.9, for the flow rate required of 10 m3
/h with viscosity
25000 cP (18519 cSt), a pump having a 100 mm dia.
inlet port would be selected.
For this example a Model SRU5/168 pump will be
selected having 100 mm dia. enlarged ports. If a
sanitary port is a definite requirement the Model
SRU6/260 pump would be selected.
To calculate pump speed for the SRU5/168 pump
selected the following formula is used as a general
guide with volumetric efficiency of 99% (see section
7.2.4).
201
7.0
Pump
Sizing

Pump 3 – Fruit Juice Concentrate and CIP
Product/Fluid data:
Fluid to be pumped - Fruit Juice Concentrate
Viscosity in pump - 200 – 1500 cP
SG - 1.1
Performance data:
Flow - 28 m3
/h
Discharge - Through pipes/bends/
valves calculated to 4 bar
Suction - Pump placed right by the
tank so friction losses to
be considered as 0 bar
Static height in tank min.
0.5 m
pt - 0 bar (open tank) = 0 m
by the customer.
Also the pump should run CIP
Fluid to be pumped - CIP
Viscosity in pump - 1 cP
Performance data:
Flow - 90 m3
/h
valves calculated to 2.5
bar
be considered as 0 bar
0.5 m
Site Services data:
7.0
Pump
Sizing

As Ht has already been informed from the customer at
4 bar we will not go further into the discharge pressure
calculation or Reynold number calculation.
Therefore:
hs = 0.5 m x (SG = 1.1) = 0.55 m
hfs = Considered to be 0
ps = 0 (open tank)
Hs = 0.55 – 0 + 0 = 0.55 m
Total Head H = Ht - Hs
H product = (4 x 10 /1.1) – 0.55 = 35.81 m (3.94 bar)
H CIP = (2.5 x 10 / 1) – 0.5 = 24.5 m (2.45 bar)
203
7.0
Pump
Sizing

NPSHa
Pa = Pressure Absolute above fluid level in Tank
Therefore:
Pa = 1 bar (open tank)
hs = 0.5 m
hfs = Assumed to be 0
Pvp = At temperature of 800
C from table 14.4 = 4.75
NPSHa CIP = 1 x 10 + 0.5 - 0 - 4.75 = 5.75 m
(Calculated for CIP as this will be lowest value due to higher temperature)
Entering the data into the selection system
we have two options:
Pump Model - DuraCirc 73 Hi-Flow
Speed - 163 / 561 rev/min
NPSHr - 0.6 / 1.1 m
Absorbed power - 4.2 / 10.6 kW - 15 kW
motor
Pump Model - OS37
(recommended speed
max. 900 rpm for juice
concentrate in a Twin
Screw pump)
NPSHr - 1.9 / 4.3 m
Absorbed power - 5.5 / 11.37 kW - 15 kW
motor
204
7.0
Pump
Sizing

With a NPSHa of 5.75 both pumps can be used with
NPSHr of 1.1 / 4.3 m.
Because the OS Twin Screw pump can run faster (in
this case 2619 rpm for the CIP), a smaller size pump
than for the DuraCirc can be chosen. In this case the
smaller Twin Screw pump will be the least expensive
pump to buy. Motor size will be the same and the
DuraCirc will only be slightly more efficient than the
Twin Screw.
Should the selection criteria be to have the most
energy efficient pump an option could be to use a
rotary lobe pump / circumferential piston pump for the
product and the centrifugal pump for the CIP. In that
case an Optilobe 53 with a 5.5 kW motor together with
a LKH-45 with an 11 kW motor (Only running during
CIP). This would save cost but also mean that there
are two pumps to install, do service on etc.
For Fruit Juice Concentrate a single flushed seal with
SiC/SiC seal faces would be recommended as this
can be quite sticky with a high sugar content. For Twin
Screw pumps we will generally recommend a flushed
seal in case the pump is running when changing
between products, so any dry running of the seal is
avoided.
205
7.0
Pump
Sizing

7.8 Worked Examples – Positive Displacement Pump Sizing
US units
The following examples show two different posi-
tive displacement pumps to be sized for a typical
sugar process and one pump to be sized for juice
concentrate.
Pump 1
A low viscosity example handling sugar syrup
Pump 2
A high viscosity example handling massecuite x
Pump 3
A double duty example handling juice concentrate
and CIP
of pump, information is required such as Product/Fluid
data, Performance data and Site Services data.
As described in section 7.1 in order to correctly
size any type of pump, information is required such
as Product/Fluid data, Performance data and Site
Services data.
206
7.0
Pump
Sizing

Pump 1 – Thin Sugar Syrup pump
Product/Fluid data:
Fluid to be pumped - Sugar Syrup
Viscosity in pump - 62 cSt (80 cP)
SG - 1.29
CIP temperature - 203° F
by the customer.
Performance data:
plus 1 bend 90° and 1
butterfly valve. Static Head
in Vessel = 26 ft. Pressure
in Vessel = 15 PSI
Suction - via 9 ft of 2 in dia. tube,
plus 2 bends 90° and 1
non-return valve
Static Head in Tank = 6 ft
Site Services data:
10 ft
15 PSI
3
ft
20
ft
6
ft
3 ft
3
ft
3 ft
Feed Tank
26
ft
Fig. 7.8a Pump 1 – example
207
7.0
Pump
Sizing

the total head and NPSHa (Fig. 7.8b). The theory, in-
cluding the different formulae regarding these parame-
ters is more specifically described in section 2.2.2 and
2.2.4.
Total head
For this example:
ht = 26 ft x (SG = 1.29) = 33.5 ft
(calculated below)
pt = 15 PSI (x 2.31/1.29) = 26.86 ft
Flow Characteristic
Reynolds number Re = 3162 x Q
D x ν
Where:
= 3162 x 40
2 x 62
= 1020
Fig. 7.8b Typical suction / Discharge Head set-up
h
t
h
s pt
ps
hfs hft
208
7.0
Pump
Sizing

is laminar, the viscosity correction factor is 1.0 (see
section 2.2.2).
(PSI)
D
Where:
D2
Where:
= 40 x 0.409
22
= 4.1 ft/s
Pf = 0.0823 x 1.29 x 0.063 x 39 x 4.12 (PSI)
2
= 2.2 PSI = 5 ft
Ht = ht + hft + pt = 33.5 + 5 + 26.86 ft = 65.36 ft ∆p = 65 ft (28.17 PSI)
Straight Tube Length = 10 + 20 + 3 = 33 ft
1 bend 90° = 1 x 3 x 1.0 (corr. factor) = 3 ft
1 butterfly valve = 1 x 3 x 1.0 (corr. factor) = 3 ft
Total equivalent length = 39 ft
Re
= 64
1020
= 0.063
209
7.0
Pump
Sizing

hs = Static suction head in Tank
hfs = Total pressure drop in suction line
For this example:
hs = 6 ft x (SG = 1.29) = 7.7 ft
hfs = calculated below
ps = 0 (open tank)
is laminar, the viscosity correction factor is 1.0
Straight Tube Length = 3 + 3 + 3 = 9 ft
2 bends 90° = 2 x 3 x 1 (corr. factor) = 6 ft
1 non-return valve = 1 x 39 x 1 (corr. factor) = 39 ft
Re
= 64
1020
= 0.063
(PSI)
D
Where:
210
7.0
Pump
Sizing

D2
Where:
= 40 x 0.409
22
= 4.1 ft/s
Pf = 0.0823 x 1.29 x 0.063 x 54 x 4.12 (PSI)
2
= 3 PSI = 7 ft
Hs = hs + hfs + ps = 7.7 - 7 + 0 ft = 0.7 ft (0.3 PSI)
Total head H = Ht – Hs = 65 - 0.7 = 64.3 ft ∆p = 64 ft (27.74 PSI)
NPSHa
Pa = Pressure Absolute above Fluid Level
in Tank
Therefore:
hs = 7.7 ft
Pvp = At temperature of 59° F this is taken
as being negligible i.e., 0 psia = 0 ft
NPSHa = Pa + hs - hfs - Pvp = 26.32 + 7.7 – 7 – 0 ft = 27.02 ft
211
7.0
Pump
Sizing

Actual pump sizing can be made using pump
performance curves or a pump selection program.
The performance curve selection procedure is more
specifically described in section 7.6.3.
14.9), a pump with a size 1.5 in inlet connection would
be required. As the duty is below 8 bar, and no special
seals or other options are needed – the Optilobe would
be the first pump to check. As the sugar syrup can be
quite abrasive with the pump we would not run much
faster than 450 rpm. Using a sizing program this gives
the pump sized as follows:
Pump Model - OptiLobe 33
Connection size - 2 in
Speed - 412 rev/min
NPSHr - 6.8 ft
Absorbed power - 1.2 hp – 1.5 hp drive
Pump Model - DuraCirc 52 Hi-Life
Speed - 407 rev/min
NPSHr - 2.1 ft
Absorbed power - 1.1 hp
Cavitation check
27.02 ft 6.8 ft.
The viscosity of 62 cSt at speed 412 rev/min is well
within the pump's maximum rated figures.
Power calculation
The power requirement is mentioned in AnyTime but it
is also possible to manually calculate as per below.
10000
Where: Pv = Power/viscosity Factor.
From example
• At speed 412 rev/min and total head 28 PSI, the
power at 1 cSt is 1.2 hp
• At viscosity 62 cSt the Pv factor is 3
10000
= 3 x 412 + 1.1
10000
= 1.22 hp
pump shaft, and the appropriate motor power must be
selected, which in this instance would be 1.5 hp being
power.
Since the viscosity is relatively low an alternative to
this could be the DuraCirc pump, which is effecient at
lower viscosity. Using the same data as above this can
be selected either in a selection program or by means
of the curves. Using a selection program the following
pump is selected.
The absorbed power is very close to that of the
Optilobe pump and as the OptiLobe will be the least
expensive technology it would be best to go with this.
The recommended type of shaft seal based upon Alfa
a single flushed mechanical seal with silicon carbide/
silicon carbide faces and EPDM or FP; elastomers.
• Hard silicon carbide seal faces due to the abrasive
nature of sugar syrup
• Flushed version to prevent the sugar syrup from
crystallising within the seal area
• EPDM or FPM elastomers for compatibility of both
sugar syrup and IP media
212
7.0
Pump
Sizing

Pump 2 – Massecuite pump
Product/Fluid data:
Fluid to be pumped - Massecuite
Viscosity in pump - 18,519 cSt
SG - 1.35
by the customer.
Performance data:
plus 2 bends 45° and 1
butterfly valve
Static head in tank = 65 ft
Suction - via 3 ft of 4 in dia. tube,
plus 1 bend 90° and 1
butterfly valve.
Static head in tank = 6 ft
Site Services data:
65
ft
6
ft
3
ft
1
3
0
f
t
Fig. 7.8c Pump 2 – example
213
7.0
Pump
Sizing

Total head
Therefore:
ht = 65 ft x (SG = 1.35) = 88 ft
(calculated below)
pt = 0 PSI = 0 ft
Flow Characteristic
D x ν
Where:
= 3162 x 44
3 x 18519
= 2.5
Fig. 7.8d
h
t
h
s pt
ps
hfs hft
7.0
Pump
Sizing
214
7.0
Pump
Sizing

valves are taken from table 14.7.2a. Since flow is lami-
nar, the viscosity correction factor is 0.25 (see section
2.2.2).
Straight Tube Length = 130 ft
2 bends 45° = 2 x 3 x 0.25 (corr. factor) = 1.5 ft
1 butterfly valve = 1 x 7 x 0.25 (corr. factor) = 1.75 ft
Re
= 64
2.5
= 25.6
(PSI)
D
Where:
D2
Where:
= 40 x 0.409
32
= 2 ft/s
Pf = 0.0823 x 1.35 x 25.6 x 133 x 22 (PSI)
3
= 504 PSI = 1163 ft
Ht = ht + hft + pt = 88 + 1163 + 0 ft = 1251 ft (542 PSI)
215
7.0
Pump
Sizing

Total suction head Hs = Hs - Hfs + ps
Where:
Pvp = Pressure in Tank (open tank)
Therefore:
hs = 6 ft x (SG = 1.35) = 8 ft
hfs = Calculated below
Ps
= 0 (open tank)
To ascertain hfs
the flow characteristic and equivalent line length must be determined as follows:
Flow Characteristic
D x ν
Where:
= 3162 x 44
4 x 18519
= 1.9
216
7.0
Pump
Sizing

and valves are taken from table 14.7.2a. Since flow is
Straight Tube Length = 3 ft
1 bend 90° = 1 x 7 x 0.25 (corr. factor) = 1.75 ft
1 butterfly valve = 1 x 7 x 0.25 (corr. factor) = 1.75 ft
Total equivalent length = 6.5 ft
Re
= 64
1.9
= 33.68
(PSI)
D
Where:
D2
Where:
= 44 x 0.409
42
= 1.1 ft/s
Pf = 0.0823 x 1.35 x 33.68 x 6.5 x 1.12 (PSI)
4
= 7.4 PSI = 17 ft
Hs = hs + hfs + ps = 8 + 17 + 0 ft = -9 ft
Total head H = Ht – Hs = 65 - 0.7 = 64.3 ft ∆p = 64 ft (27.74 PSI)
laminar, the viscosity correction factor is 0.25
217
7.0
Pump
Sizing

Speed - 87 rev/min
NPSHr - 2.1 ft
Absorbed power - 16.4 hp
Because of the high total head the only pump which
would be able to handle this would be the DuraCirc.
Through the selection program the below is found.
It could however be an idea to consider reducing the
head so a smaller pump can be suitably sized, consid-
eration could be given to any or a combination of the
following parameters:
1. Reduce capacity
2. Increase tube diameter
3. Increase pumping temperature to reduce viscosity
Using the Miller equation to determine friction loss as follows:
Pf = 0.00823 x SG x fD x L x V2
(PSI)
D
Where:
L = Tube Length (m)
= 0.00823 x 1.35 x 33.68 x 133 x 1.12 (PSI)
4
= 150 PSI = 346 ft
Now Ht = ht + hft + pt = 88 + 346 + 0 ft = 434 ft (188 PSI)
Now Total Head H = Ht - Hs = 434 - (- 9) = 443 ft (192 PSI)
Assuming the capacity is a definite requirement and
the pumping temperature cannot be increased the
customer could increase the discharge tube diameter
i.e. from 3 inch to 4 inch.
The total head calculations are reworked, and for this
particular example the fluid velocity (V) and friction
factor (fD) have already been established for 4 in
diameter tube. Also note, by referring to the equivalent
tube length table 14.7.2a the values for bends 450
and
butterfly valves remain unchanged.
218
7.0
Pump
Sizing

219
7.0
Pump
Sizing
219
7.0
Pump
Sizing

NPSHa
For this example:
Pa = 14.7 bar (open tank) = 25.15 ft (SG 1.35)
hs = 8 ft
F this is taken as being
negligible i.e. 0 psia = 0 ft
NPSHa = Pa + hs - hfs - Pvp = 25.15 + 8 – 17 – 0 m = 16.15 ft
Pump Model - SRU5/168/LD
Connection size - 4 in (enlarged port)
Speed - 100 rev/min
NPSHr - 7.5 ft
Absorbed power - 6.5 hp - 7.5 hp drive
With the new head an SRU pump or a smaller
DuraCirc circumferential piston pump could be
an option and using a pump selection program
using stainless steel Tri-lobe rotors with 130°C
rotor clearances would be as follows:
Note that by increasing the pipe size the energy
consumption is reduced from 16.4 to 6.8 hp.
Speed - 84 rev/min
NPSHr - 2.1 ft
Absorbed power - 6.8 hp - 7.5 hp drive
220
7.0
Pump
Sizing

Alternative Pump Sizing Guide Using
Volumetric Efficiency Calculation
Referring to the initial suction line sizing curve
shown in section 14.9, for the flow rate required
of 44 US gal/min with viscosity 18519 cSt, a pump
having a 100 mm dia. inlet port would be selected.
For this example a Model SRU5/168 pump will be
selected having 4 in dia. enlarged ports.
Pump speed (rev/min) n = Q x 100
q x ηv
Where:
= 44 x 100
44.39 x 0.99
= 100 rev/min
Cavitation check
NPSHa should be greater than NPSHr i.e., 16.15 ft
7.5 ft / 2.1 ft.
The viscosity of 18519 cSt at speed 100 rev/min is well
within the pump’s maximum rated figures.
It should be noted that this is the power needed at
the pump shaft, and for a fixed speed drive the
appropriate motor power must be selected, which in
this instance would be 7.5 hp being the nearest motor
output power above the required power.
As the SRU will be the least expensive technology this
would be best to go with in this case.
a single flushed seal with SiC/SiC seal faces and FPM
or EPDM elastomers.
It is important to notice that in the above we have had
information about the in-pump viscosity. There can
be a large difference between the viscosity at rest
and the in-pump viscosity. In our selection system we
have information about the typical in-pump viscosity
for a variety of products. If in doubt about a product,
it could be worth getting it tested in order to get the
correct viscosity.
If a sanitary port is a definite requirement the Model
SRU6/260 pump would be selected.
To calculate pump speed for the SRU5/168 pump
selected the following formula is used as a general
guide with volumetric efficiency of 99% (see section
7.2.4).
221
7.0
Pump
Sizing

Pump 3 – Fruit Juice Concentrate and CIP
Product/Fluid data:
Fluid to be pumped - Fruit Juice Concentrate
Viscosity in pump - 200 – 1500 cP
SG - 1.1
Performance data:
Flow - 123 GPM
valves calculated to 58 PSI
be considered as 0 PSI.
1.64 ft
pt - 0 PSI (open tank) = 0 ft
by the customer.
Also the pump should run CIP
Fluid to be pumped - CIP
Viscosity in pump - 1 cP in pump
Performance data:
Flow - 396 m3
/h
valves calculated to 36.26
PSI
be considered as 0 PSI.
1.64 ft
Site Services data:
222
7.0
Pump
Sizing

As Ht has already been informed from the customer
at 58 PSI / 36.26 PSI, calculations for discharge pres-
sure and Reynold number will not be made.
Therefore:
hs = 1.64 for CIP (for product x (SG = 1.1) = 1.8 ft)
hfs = Considered to be 0
ps = 0 (open tank)
Hs = 1.8 – 0 + 0 = 1.8 ft
Total Head H = Ht - Hs
H product = (58 x 2.31 /1.1) – 1.8 = 120 ft (57 PSI)
H CIP = (36.26 x 2.31) – 1.64 = 74.35 m (32.22 PSI)
223
7.0
Pump
Sizing

NPSHa
Therefore:
hs = 1.8 ft
hfs = Assumed to be 0
C / 1760
F from
table 14.4 = 47.5
kPa = 15.9 ft
NPSHa CIP = 33.5 + 1.64 - 0 - 15.9 = 19.24 ft
(Calculated for CIP as this will be lowest value due to higher temperature)
Entering the data into the selection system
we have two options:
Pump Model - DuraCirc 73 Hi-Flow
Connection size - 4 in / 3 in
NPSHr - 2 / 3.5 ft
Absorbed power - 5.5 / 13.9 hp - 20 hp
motor
Pump Model - OS37
(recommended speed
max. 900 rpm for juice
concentrate in a Twin
Screw pump)
NPSHr - 6.4 / 14.1 ft
Absorbed power - 8.23 / 15.19 hp - 20 hp
motor
224
7.0
Pump
Sizing

With a NPSHr of 14.1 both pumps can be used with
NPSHa of 19.24 ft.
Because the OS Twin Screw pump can run faster (in
this case 2617 rpm for the CIP), a smaller size pump
than for the DuraCirc can be chosen. In this case the
smaller Twin Screw pump will be the least expensive
pump to buy. Motor size will be the same and the
DuraCirc will only be slightly more efficient than the
Twin Screw.
Should the selection criteria be to have the most
energy efficient pump an option could be to use a
rotary lobe pump / circumferential piston pump for the
product and the centrifugal pump for the CIP. In that
case an Optilobe 53 with a 10 hp drive together with a
LKH-45 with an 5 hp motor (Only running during CIP).
This would save cost but also mean that there are two
pumps to install, do service on etc.
For Fruit Juice Concentrate a single flushed seal with
SiC/SiC seal faces would be recommended as it will
have a high sugar content and can be very sticky.
225
7.0
Pump
Sizing

This chapter gives descriptions of
the various specification options
available for the Alfa Laval pump
ranges, such as port connections,
heating/cooling jackets, pressure
relief valves and other ancillaries.
226
8.0
Pump
Specification
Options

Pump Specification
Options
8.0
227
8.0
Pump
Specification
Options

8.1.1 Port Connections
Pumps are supplied with unions, clamp fittings and
flanges to all main standards, i.e., SMS, DIN, ISO,
ASME, BS, DS, bevel seat, DC and H-Line.
Pump Range Pump Model Nominal Connection Size
Inlet mm Outlet mm Inlet in Outlet in
LKH LKH 5 50 40 2 1.5
LKH 10 65 50 2.5 2
LKH 15 100 80 4 3
LKH 20 65 50 2.5 2
LKH 25 80 65 3 2.5
LKH 35 65 50 2.5 2
LKH 40 80 65 3 2.5
LKH 45 100 80 4 3
LKH 50 100 80 4 3
LKH 60 100 100 4 4
LKH 70 100 80 4 3
LKH 75 100 100 4 4
LKH 85 150 150 6.0 6.0
LKH 90 150 150 6.0 6.0
LKH-Multistage LKH 112 50 40 2.0 1.5
LKH 113 50 40 2.0 1.5
LKH 114 50 40 2.0 1.5
LKH 122 80 65 3.0 2.5
LKH 123 80 65 3.0 2.5
LKH 124 80 65 3.0 2.5
LKHPF LKHPF 10 65 50 2.5 2.0
LKHPF 15 100 80 4.0 3.0
LKHPF 20 65 50 2.5 2.0
LKHPF 25 80 65 3.0 2.5
LKHPF 35 65 50 2.5 2.0
LKHPF 40 80 65 3.0 2.5
LKHPF 45 100 80 4.0 3.0
LKHPF 50 100 80 4.0 3.0
LKHPF 60 100 100 4.0 4.0
LKHPF 70 100 80 4.0 3.2
228
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Options

LKH Evap LKH Evap 10 65 50 2.5 2.0
LKH Evap 15 100 80 4.0 3.0
LKH Evap 20 65 50 2.5 2.0
LKH Evap 25 80 65 3.0 2.5
LKH Evap 35 65 50 2.5 2.0
LKH Evap 40 80 65 3.0 2.5
LKH Evap 45 100 80 4.0 3.0
LKH Evap 50 100 80 4.0 3.0
LKH Evap 60 100 100 4.0 4.0
LKH Evap 70 100 80 4.0 3.0
LKH UltraPure LKH UltraPure 10 65 50 2.5 2.0
LKH UltraPure 20 65 50 2.5 2.0
LKH UltraPure 45 100 80 4.0 3.0
LKH UltraPure 60 100 100 4.0 4.0
LKH UltraPure 70 100 80 4.0 3.0
LKH Prime LKH Prime 10 50 50 2.0 2.0
LKH Prime 20 65 50 2.5 2.0
LKH Prime 40 80 65 3.0 2.5
LKH Prime UltraPure LKH Prime UltraPure 10 50 50 2.0 2.0
LKH Prime UltraPure 20 65 50 2.5 2.0
SolidC SolidC 1 50 40 2.0 1.5
SolidC 2 65 40 2.5 1.5
SolidC 3 80 40 3.0 1.5
SolidC 4 80 50 3.0 2.0
Table 8.1.1a
229
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Options

8.1.2 Heated/Cooled Pump Casing
In some applications, heating of the fluid being
pumped may be required to reduce the fluid viscosity
so that satisfactory operation is achieved. Alternatively,
it may be necessary to cool the fluid being pumped
where heat is generated by means of the fluid re-
peatedly being passed through the pump. On such
occasions most LKH pump models can be fitted with
heating/cooling jacket (Fig. 8.1.2a).
8.1.3 Drainable Pump Casing
In applications where it is a requirement that no
fluid should be left in the pump casing. This can
be achieved by either turning the pump outlet down-
wards, fitting a drain connection or welding a valve
to the bottom of the pump casing (Fig. 8.1.3a, 8.1.3b,
8.1.3c).
Fig. 8.1.2a Heating/Cooling jacket on the LKH pump
Fig. 8.1.3b Pump casing with drain connection
Fig. 8.1.3a Turned pump casing
Fig. 8.1.3c Pump casing with Unique DVST valve
Pump casing
Heating jacket 0° 45°
90° 270°
230
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Options

8.1.4 Clear Flow Impeller
In some applications, e.g. when using an LKH centrifu-
gal pump as a booster pump in a cream pasteurisation
unit, there is a risk that a hard layer of proteins will
slowly build up between the backside of the impeller
and the back plate. This will activate the thermal relay
of the motor after a few hours of operation so that the
pump stops.
The operating time of the pump can be increased by
applying a clear flow impeller (Fig. 8.1.4a). The clear
flow impeller is a special scraper impeller that solves
the product build-up problem by increasing the stand-
ard gap width between the back of the impeller and
the back plate. By introducing scrapers on the back of
the impeller the hard layer is constantly removed.
When sizing pumps with clear flow impeller it must be
taken into account that the head will be reduced by
up to 10%. Furthermore, for this type of application, it
is recommended to select a motor size with an output
power one rating higher than the standard selection to
avoid the motor thermal relay being constantly tripped.
8.1.5 Inducer
In some applications, it may be necessary to improve
suction conditions by means of fitting the pump with
an inducer (Fig. 8.1.4b).
This has the effect of improving NPSHr for difficult
applications and/or assisting the flow of a viscous fluid
into the pump casing.
Alfa Laval’s LKH pump ranges are acknowledged as
having one of the best NPSHr characteristics on the
market without the requirement of an inducer to the
impeller; a more likely utilisation would be handling
those higher viscosity applications where transition
from inlet to impeller eye requires assistance.
8.1.6 Motor
Centrifugal pumps are generally available with 2 pole
and 4 pole motors with synchronous speeds of 3000
and 1500 rev/min for 50 Hz and 3600 and 1800 rev/
min for 60 Hz, respectively.
A stainless-steel protective shroud is standard with IEC
motors. Electric motors are described in more detail in
chapter 9.
Fig. 8.1.4a Clear flow impeller Fig. 8.1.4b LKH inducer
231
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Specification
Options

8.1.7 Legs
As standard centrifugal pumps are supplied with
adjustable feet and legs to enable easy installation
and commissioning (Fig. 8.1.7a).
LKH pumps are also optionally available with adjust-
able pads with covered threads surfaces and sealing
between all moveable parts of the legs and thereby
reduce the cleaning effort to a minimum (Fig. 8.1.7b).
8.1.8 Other Centrifugal Pump Specification Options
There are also centrifugal pump options available to
meet specific application demands related to internal
surface finish (see chapter 5), elastomer material (see
chapter 5) and shaft seal design (see chapter 6).
Fig. 8.1.7a Adjustable legs Fig. 8.1.7b Adjustable pads
232
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Specification
Options

8.2 Positive Displacement Pumps
8.2.1 Rotor Form
Overview of Rotor form to positive displacement pumps:
Pump Type Rotor Rotor Material
DuraCirc Circumferential Piston Bi-piston Non galling alloy
OptiLobe Rotary Lobe Tri-lobe Stainless steel
SRU Rotary Lobe Tri-lobe Stainless steel
Bi-lobe Stainless steel
Bi-lobe Non galling alloy
SX Rotary Lobe Multi-lobe Stainless steel
SX UltraPure Rotary Lobe Multi-lobe Stainless steel
OS Twin Screw Screw Stainless steel
Table 8.2.1a
233
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Options

8.2.1.2 Rotary Lobe Pumps
Tri-lobe Rotors (Stainless steel)
Most duties can be accomplished by pumps fitted
with stainless steel Tri-lobe rotors (Fig. 8.2.1.2a). The
Tri-lobe rotor with its geometrically optimized profile
and precision manufacture ensure interchangeability
as well as smooth, high performance pumping action.
These are available on the SRU pump range with three
temperature ratings:
• Up to 70° C (158° F)
• Up to 130° C (266° F)
• Up to 200° C (392° F)
And pressures up to 20 bar (290 PSIG)
On the OptiLobe range Tri-lobe rotors are suitable for
temperatures up to 130° C (266° F) and pressures up
to 8 bar (116 PSIG).
8.2.1.1 Circumferential Piston Pumps
DuraCirc pumps have Bi-piston rotors manufactured
from non-galling alloy to allow for very small clearanc-
es (see section 8.2.2), leading to very high efficiencies.
High volumetric efficiency is particularly important in
applications where there is a combination of low vis-
cosity and high pressure. DuraCirc rotors are suitable
for temperatures up to 150° C (302° F) and pres-
sures up to 40 bar (580 PSIG) (Fig. 8.2.1.1a and Table
8.2.1.1a).
Model Max. Solids
mm in
DuraCirc 32 8 0.3
DuraCirc 33 8 0.3
DuraCirc 34 13 0.5
DuraCirc 42 13 0.5
DuraCirc 43 13 0.5
DuraCirc 52 17 0.7
DuraCirc 53 21 0.8
DuraCirc 54 25 1.0
DuraCirc 62 25 1.0
DuraCirc 63 34 1.3
DuraCirc 72 34 1.3
DuraCirc 73 51 2.0
DuraCirc 74 51 2.0
Table. 8.2.1.1a The maximum spherical solids size that can
be satisfactory handled without product degradation on
DuraCirc circumferential piston pumps
Fig. 8.2.1.2a Tri-lobe rotor
Fig. 8.2.1.1a DuraCirc Bi-piston Rotors
234
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Options

Bi-lobe Rotors (Stainless steel)
These are generally used for handling delicate
suspended solids where minimum product damage
is required (Fig. 8.2.1.2b - 8.2.1.2c). Typical applications
are jam containing fruit pieces, sausage meat filling,
petfood, soups and sauces containing solid matter.
Bi-lobe rotors in stainless steel are available on the
SRU pump range with three temperature ratings:
• Up to 70° C (158° F)
• Up to 130° C (266° F)
• Up to 200° C (392° F)
SRU Model Bi-lobe Rotors Tri-lobe Rotors
mm in mm in
SRU1/005 8 0.31 6 0.24
SRU1/008 8 0.31 6 0.24
SRU2/013 8 0.31 6 0.24
SRU2/018 13 0.51 9 0.34
SRU3/027 13 0.51 9 0.34
SRU3/038 16 0.63 11 0.44
SRU4/055 16 0.63 11 0.44
SRU4/079 22 0.88 15 0.59
SRU5/116 22 0.88 15 0.59
SRU5/168 27 1.06 18 0.72
SRU6/260 27 1.06 18 0.72
SRU6/353 37 1.47 24 0.94
Table. 8.2.1.2a The maximum spherical solids size that can be satisfactory handled without product degradation on SRU rotary lobe pumps
Fig.8.2.1.2b Bi-lobe rotor Fig.8.2.1.2c Bi-lobe rotors for solids handling
235
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Specification
Options

Multi-lobe Rotors
This rotor is manufactured from stainless steel and
as the name suggests has many lobes. For the SX
and the SX UltraPure pump range these rotors have 4
lobes and are designed to maximise efficiency, reduce
shear and provide a smooth pumping action (Fig.
8.2.1.2d and Table 8.2.1.2b). Rotors are suitable for
temperatures up to 150° C (302° F) and pressures up
to 15 bar (215 PSIG).
SX Model Multi-lobe Rotors
mm in
SX1/005 7 0.28
SX1/007 7 0.28
SX2/013 10 0.39
SX2/018 10 0.39
SX3/027 13 0.51
SX3/035 13 0.51
SX4/046 16 0.63
SX4/063 16 0.63
SX5/082 19 0.75
SX5/115 19 0.75
SX6/140 25 0.98
SX6/190 25 0.98
SX7/250 28 1.1
SX7/380 28 1.1
Table. 8.2.1.2b The maximum spherical solids size that
can be satisfactory handled without product degradation
on SX rotary lobe pumps
Bi-lobe Rotors (Non galling alloy)
Manufactured from non-galling alloy these rotors
have an advantage over stainless steel, as smaller
clearances (see section 8.2.2) can be used, leading
to increased volumetric efficiency on lower viscosity
applications.
These are available on the SRU pump range with 3
temperature ratings:
• Up to 70° C (158° F)
• Up to 130° C (266° F)
• Up to 200° C (392° F)
Fig.8.2.1.2d Multi-lobe rotor
236
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Options

8.2.1.3 Twin Screw Pumps
OS Twin Screw Pumps have screws made from 316L
stainless steel. Different screw profiles are available.
Each screw has a specific pitch length which is basi-
cally the dimension from the rear face of one helix to
the front of the next helix. A tighter pitch for the same
length screw will have more closed chambers and as
such less slip and greater pressure build up.
The chamber is the free distance between the rear
of one helix and the front of the next helix in which
product is moved, to this extent the chamber size for
a given screw length determines the flow rate and the
maximum particle size for solids handling (Fig. 8.2.1.3a.
Screws are suitable for pressures up to 16 bar. For
continuous operation they are suitable for tempera-
tures up to 100° C (212° F) and for intermittent opera-
tion up to 150° C (302° F).
Pitch Chamber Size (mm)
Defines max. solids size
OS1* OS2* OS3* OS4*
*2 6 13 16.5 22.5
*4 11 17.5 23 31
*6 17 26 33.5 45.5
*7 - 15 20 -
*8 - 32 42 -
Chamber Size (in)
Defines max. solids size
OS1* OS2* OS3* OS4*
0.24 0.51 0.65 0.89
0.43 0.69 0.9 1.22
0.67 1.02 1.32 1.79
- 0.59 0.79 -
- 1.26 1.65 -
Table. 8.2.1.3a The maximum spherical solids size that can be satisfactory handled without product degradation on OS twin screw pumps.
Fig. 8.2.1.3a Screw pitch (A) and chambers (B)
B
A
237
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8.2.2 Clearances
Within the pump head are clearances, which are the
spaces between rotating components and between
rotating and stationary components (Fig. 8.2.2a).
The key clearances are as follows:
• Radial clearance
(between rotor tip and casing)
• Mesh clearance
(between rotors)
• Front clearance
(between front of rotor and casing cover)
Clearances are necessary to
avoid rotor to rotor, rotor to cas-
ing and rotor to casing cover
contact (likewise for screws).
The size of these clearances
is related to the pressure and
temperature of pump operation
and rotor material.
• Back clearance
(between back of rotor and back face of casing)
• Root clearance
(applicable to twin screw pumps; between the
mesh of the screws)
Fig. 8.2.2a Clearances in a rotary lobe pump
Radial
Mesh
238
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Options

Pressure effect
The design concept of the rotary positive displacement
pump is to have no contacting parts in the pump head.
This requires having the shaft support bearings mount-
ed outside of the pump head, which results in an over-
hung load, caused by the rotors/screws fitted to the
shafts (see Fig. 8.2.2b). The effect of pressure on the
rotors will cause shaft deflection, which could result in
contact between rotors, casing and casing cover. As
product wetted parts of the rotary lobe and twin screw
pump ranges are predominantly manufactured from
stainless steel, any contact between rotating and sta-
tionary parts would cause ‘galling’ and possible pump
seizure. To allow for this pressure effect, clearances
are built into the pump head between surfaces that
may contact. For the OptiLobe, SRU, SX, SX UltraPure
and OS pump ranges there is only one pressure
rating, which is the maximum differential pressure of
the particular pump model. The pressure effect is less
significant on pumps fitted with non-galling alloy rotors
like the DuraCirc circumferential piston pump.
Temperature effect
Temperature change can be caused by the fluid being
pumped, pump mechanism, drive unit and/or the
environment. Any CIP operation required should also
be taken into consideration (see chapter 10 for detailed
explanation of CIP). Changes in temperature will cause
expansion upon heating or contraction upon cooling,
to the pump casing and gearcase components. The
most significant result is movement between shaft and
gearcase/pump casing causing the rotors to move for-
ward/backward in the pump casing, thereby reducing
the front clearance. To compensate for this, the SRU
pump range has increased clearances as shown be-
low. SRU pumps are designed for various temperature
ratings for rotors i.e., 70° C (158° F), 130° C (266° F) or
200° C (392° F).
On other Alfa Laval rotary positive displacement pump
ranges the design of the mechanical seal eliminates
contact between the fluid being pumped and the shaft.
This results in the shaft not being subjected to the full
temperature variation and therefore only one tempera-
ture rating of 150° C (302° F) is necessary.
Fig. 8.2.2b Pressure effect on rotary lobe and circumferential
piston pumps
Support Bearing
Force due to pressure
Overhang length
Rotor
Shaft
239
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Specification
Options

8.2.3 Port Connections
Alfa Laval rotary positive displacement pumps are
supplied with connections to all major standards
(please refer to Anytime for full listing of available port
connection standard by pump range). All models have
full bore through porting, conforming to International
Sanitary Standards BS4825 / ISO2037. This provides
effective CIP cleaning and maximises inlet and outlet
port efficiency and NPSHr characteristics.
On SRU pump models there is an option of an en-
larged port which can be chosen for high viscosity
applications.
On DuraCirc pump models the Uni-Fit option is availa-
ble whereby the pump is supplied with the same port
to port and foot to port centre dimensions as the old
Alfa Laval SCPP pump, enabling ease of replacement
without design or pipework modification. On DuraCirc
34 and 42 the port size dimension is reduced when
the Uni-Fit option is specified.
Standard Optional
mm in mm in
DuraCirc DuraCirc 32 25 1 - -
DuraCirc 33 40 1.5 - -
DuraCirc 34 50 2 40 1.5
DuraCirc 42 50 2 40 1.5
DuraCirc 43 50 2 - -
DuraCirc 53 65 2.5 - -
DuraCirc 63 100 4 - -
DuraCirc 72 100 4 - -
DuraCirc 73 150 6 - -
DuraCirc 74 150 6 - -
OptiLobe OptiLobe 12 25 1 - -
OptiLobe 13 40 1.5 - -
OptiLobe 22 40 1.5 - -
OptiLobe 23 40 1.5 - -
OptiLobe 32 50 2 - -
OptiLobe 42 65 2.5 - -
OptiLobe 53 100 4 - -
240
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Specification
Options

Standard Optional
mm in mm in
SRU SRU1/005 25 1 - -
SRU1/008 25 1 40 1.5
SRU2/013 25 1 40 1.5
SRU2/018 40 1.5 50 2
SRU3/027 40 1.5 50 2
SRU3/038 50 2 65 2.5
SRU4/055 50 2 65 2.5
SRU4/079 65 2.5 80 3
SRU5/116 65 2.5 80 3
SRU5/168 80 3 100 4
SRU6/260 100 4 100 4
SRU6/353 100 4 150 6
SX SX1/005 25 1 - -
SX1/007 40 1.5 - -
SX2/013 40 1.5 - -
SX2/018 50 2 - -
SX3/027 50 2 - -
SX3/035 65 2.5 - -
SX4/046 50 2 - -
SX4/063 65 2.5 - -
SX5/082 65 2.5 - -
SX5/115 80 3 - -
SX6/140 80 3 - -
SX6/190 100 4 - -
SX7/250 100 4 - -
SX7/380 150 6 - -
Table 8.2.3b Port size on rotary lobe and circumferential piston pumps
241
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Options

Flanges for vertically ported circumferential piston and
rotary lobe pumps are not fitted directly to the dis-
charge port. In this instance an elbow bend is required
to which the flange is fitted.
Due to the wide performance envelope with twin screw
pumps there are multiple inlet/outlet combinations
available. As with centrifugal pumps the basic recom-
mendation is that the port size on the outlet should
max. be the size of the inlet port.
OS OS 12/14/16 40 25 1.5 1
40 40 1.5 1.5
50 25 2 1
50 40 2 1.5
50 50 2 2
65 25 2.5 1
65 40 2.5 1.5
65 50 2.5 2
OS 22/23/24 50 40 2 1.5
50 50 2 2
65 40 2.5 1.5
65 50 2.5 2
65 65 2.5 2.5
80 40 3 1.5
80 50 3 2
80 65 3 2.5
OS 32/34/36 80 65 3 2.5
80 80 3 3
100 65 4 2.5
100 80 4 3
OS 42/44/46 100 80 4 3
100 100 4 4
150 80 6 3
150 100 6 4
Table 8.2.3c Port size options on twin screw pumps (conventional flow direction)
8.0
Pump
Specification
Options

8.2.4 Rectangular Inlet
For handling extremely viscous products and/or large
solids that would naturally bridge a smaller port, SRU
rotary lobe pumps, DuraCirc circumferential piston
pumps and OS twin screw pumps can be supplied
with a rectangular inlet (Fig. 8.2.4a - 8.2.4b). Usually,
the inlet port will be in vertical orientation to allow the
product to flow into the pumping chamber under grav-
ity from a hopper mounted directly above or mounted
with an adaptor to facilitate connection to large diame-
ter pipework.
As can be seen from the tables below for pumps with
rectangular inlets, there is a percentage area increase
when compared to a sanitary port connection. This
increases the pump’s ability to handle highly viscous
products.
Pump Model Sanitary Port Rectangular Inlet % Area Increase above Sanitary
Area (mm2
) Area (mm2
) Port Diameter
SRU1/005 387 660 +71
SRU1/008 387 1260 +226
SRU2/013 387 1216 +214
SRU2/018 957 1976 +106
SRU3/027 957 2112 +121
SRU3/038 1780 3360 +89
SRU4/055 1780 2688 +51
SRU4/079 2856 4320 +51
SRU5/116 2856 5032 +76
SRU5/168 4185 8160 +95
SRU6/260 7482 13888 +86
SRU6/353 7482 18240 +144
Table 8.2.4a Port size impact on SRU rotary lobe pumps with rectangular inlet
Pump Size Standard Port Rectangular Port
Diameter
mm
Area
mm2
Length
mm
Width
mm
Radius
mm
Area
mm2
% Increase over
Standard Port Area
DuraCirc 33 34.9 957 120 20 10 2314 +142
DuraCirc 42 47.6 1780 145 30 15 4157 +134
DuraCirc 53 60.3 2856 206 40 15 8047 +182
DuraCirc 54 73.0 4185 206 62 15 12579 +201
DuraCirc 62 73.0 4185 248 50 19 12090 +189
DuraCirc 63 97.6 7482 248 70 19 17050 +128
DuraCirc 72 97.6 7482 284 48 20 13289 +78
DuraCirc 73* 120.0 11310 284 70 20 19537 +73
* DuraCirc 73 uses a 150 mm port with a 120 mm weld neck diameter
Table 8.2.4b Port size impact on DuraCric circumferential piston pumps with rectangular inlet
Fig. 8.2.4a DuraCirc circumferential piston pump with rectangular inlet
243
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Options

Pump Model Default Port Size
(cover)
Area of Default
Port (mm2
)
Dimensions
Rectangle (mm)
Area of Rectangle
(mm2
)
% Area Increase
OS10 DN65 3421.19 65 x 48 3120 -8.8
OS20 DN80 5153.00 90 x 50 4500 -12.67
OS30 DN100 7853.98 110 x 65 7150 -8.96
OS40 DN150 17671.49 150 x 80 12000 -32.09
Table 8.2.4c Port size impact on OS twin screw pumps with rectangular inlet
Fig. 8.2.4b OS Twin Screw pump with rectangular inlet
244
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Options

8.2.5 Heated/Cooled Pump Casing
Rotary lobe, circumferential piston as well as twin
screw pumps facilitate heating/cooling to improve
handling of temperature sensitive products, maintain
media viscosity and reduce risk of crystallization or
solidification.
Typical applications include:
• Adhesive
• Chocolate
• Gelatine
• Jam
• Resin
Solutions are designed to ensure a significant temper-
ature impact on the pump casing. The exact solution
depends on the specific technology in question, but
as a general rule, heating/cooling devices should be in
operation prior to pump start up and remain in opera-
tion for some time after pump shut down.
Operation prior to
Pump Start Up
Operation after
Pump Shut Down
Max. Temperature
Heating Fluid
Max. Pressure
Heating/Cooling Fluid
DuraCirc 30-70 15 minutes 15 minutes 150° C (302° F) 3.5 bar (50 PSIG)
SRU 1-6 15 minutes 15 minutes 150° C (302° F) 3.5 bar (50 PSIG)
SX 1-7 15 minutes 15 minutes 150° C (302° F) 3.5 bar (50 PSIG)
OptiLobe 10-30 30 minutes 30 minutes 150° C (302° F) 3.5 bar (50 PSIG)
OptiLobe 40-50 45 minutes 45 minutes 150° C (302° F) 3.5 bar (50 PSIG)
OS 10-40 15 minutes 15 minutes 150° C (302° F) 10 bar (145 PSIG)
Table 8.2.5a Operational data, heating/cooling devices
245
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Specification
Options

8.2.5.1 Circumferential Piston Pumps
DuraCirc pumps are pre-drilled to accept bolt-on
heating/cooling jackets with O-ring elastomer sealing
on the rear of the pump casing. Jackets are therefore
retrofittable to installed pumps also (Fig. 8.2.5.1a).
8.2.5.2 Rotary Lobe Pumps
Heating/cooling jackets on the front cover are available
on both the OptiLobe, SRU and SX pump ranges, but
saddles are only available on the SRU pump range
(Fig. 8.2.5.2a - 8.2.5.2b).
Fig. 8.2.5.1a Heating elements fitted to casing on DuraCirc
Fig. 8.2.5.2a SRU rotary lobe pump with heating/cooling jacket and saddle Fig. 8.2.5.2b OptiLobe rotary lobe pump with heating/cooling cover
Saddle
Jacket
Connections for steam,
hot/cold fluid
8.0
Pump
Specification
Options

8.2.5.3 Twin Screw Pumps
On OS pumps the heating/cooling device option is
fitted in the form of a modified casing including link
piping between the heating/cooling chambers (Fig.
8.2.5.3a).
8.2.6 Pump Overload Protection
Due to the positive action of the positive displacement
pump any restriction on the outlet side of the pump,
either partial or total, will result in excessive pressure
developing in the pump casing. It is therefore rec-
ommended that some form of overload protection
is installed to protect the pump, drive unit and also
limit pressure build up within associated process
equipment.
By-pass loop
With a by-pass loop, excess pressure will be relieved
by bypassing the product through a loop back to the
suction side of the pump (Fig. 8.2.6a). This protection
will normally take the form of an external spring-load-
ed pressure relief valve fitted to the outlet side of the
pump which will open under high pressure and allow
fluid to return to the inlet side of the pump.
Fig. 8.2.5.3a OS Twin Screw pump with heating/cooling jacket
Fig. 8.2.6a Bypass/pressure relief configuration
247
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Options

Pressure Relief Valves
On SRU rotary lobe pumps it is also possible to supply
a pressure relief valve as an integral part of the pump
which means that external pipework is not required –
It is important to note, this is a pump protection relief
valve only, it is not to be utilized as a system relief
valve, to which an external valve arrangement such
as the by-pass loop would be required (Fig. 8.2.6b).
To fit a pressure relief valve a special rotor case cover
is required. The valve will provide full pump protection
for fluids having viscosities below 500 cP, above this
figure Alfa Laval should be consulted with regard to
specific flow rates in relation to viscosity and differ-
ential pressures. The design is such that the valve
mechanism is isolated from the pumped fluid.
As it is a mechanical device the relief valve does not
operate instantaneously due to mechanical response
time. The valve will begin to relieve at a pressure less
than the fully open pressure (Fig. 8.2.6c). This ‘accu-
mulation’ will vary depending upon the duty pressure,
viscosity and pump speed. The accumulation tends
to increase as pressure or pump speed decrease,
and as viscosity increases. The valve is set to relieve
at the required pressure by the correct choice of
springs and can be adjusted on site to suit actual duty
requirements.
Pressure relief valves are only available for SRU pumps
fitted with metal rotors. They can be retrofitted to
installed pumps and pumps will still be suitable for
bi-direction operation.
Fig. 8.2.6b SRU rotary lobe pump with pressure relief valve
Fig. 8.2.6c Relief valve operation
Pressure
Relief Valve
Product passes through
open slip path
Piston opens when preset
pressure reached
248
8.0
Pump
Specification
Options

The relief valve can be provided with the following
options:
• Automatic with Pneumatic Override
This valve may be pneumatically overridden for
CIP conditions, and it may be remotely controlled
if required. Air supply should be clean and dry at
pressures of 4 bar (60 PSIG) minimum and 8 bar
(115 PSIG) maximum
• Automatic with Manual Override
This valve has a lever to enable manual override for
CIP or certain tank filling applications
Valve Type Pump Range - Availability Normal Operating Pressure Range
bar PSIG
Standard SRU1-6 7-19 100-5
Pneumatic override SRU1-6 7-19 100-5
Manual override SRU1-3 19 5
SRU4-5 7-10 100-145
SRU6 7 100
Table 8.2.6a SRU pressure relief valve overview
249
8.0
Pump
Specification
Options

8.2.7 Surface hardening
Care should be taken when handling abrasive media,
i.e., products such as inks have very fine particles,
whilst other products such as sugar slurries, can con-
tain much larger particles which can lead to excessive
pump wear.
To combat this issue, consideration needs to be
given to pumping speed, temperature and differential
pressure.
Depending upon the abrasion level of the product;
consideration should be given to include for the addi-
tional hardened option to improve wear resistance.
8.2.7.1 Rotary lobe pumps
Alfa Laval SRU pumps can be specified with diffusion
hardening to obtain a very high surface hardness
rating between 1200-1400 HV0.05 with diffusion depth
of 25 μm.
Hardening is applied to the pump-head which covers
the casing, rotors, rotor nuts and front cover.
8.2.7.2 Twin Screw pumps
The Alfa Laval Twin Screw pump has hardened pump-
head casing as the default.
Surface hardness measurement - typically 1092
HV0.05 with diffusion depth of 25.5 μm and can be
an option to also harden the screws for the highly
abrasive media.
Alfa Laval recommends an absolute operational limit
of 600 rpm for twin screw pumps on any media that
could be considered “abrasive”.
It is important to note, diffusion hardening is a process
that does not reduce material chemical resistance (not
a coating and does not change the chemical compo-
sition of the surface), therefore unlike other traditional
hardening processes such as plasma nitriding, which
reduces chemical resistance, can be considered suita-
ble for use in hygienic applications.
8.2.8 Ancillaries
Positive displacement pumps can be supplied with
bare shaft (without drive) or mounted on a baseplate
with an electric motor. Electric motors are described in
more detail in chapter 9.
Drives
Rotary lobe and circumferential piston pumps gener-
ally operate at low to medium speeds i.e., 25 to 650
rev/min, and therefore some form of speed reduction
is often required from normal AC motor synchronous
speeds of 1500, 1000 and 750 rev/min for 50 Hz
(1800, 1200 and 900 rev/min for 60 Hz). This is gener-
ally achieved by using a geared electric motor direct
coupled to the pump drive shaft via flexible coupling.
When exact flow is not critical a fixed speed drive
is generally used. The integral geared electric mo-
tor is the most commonly used type of fixed speed
drive. This is a compact unit, which is easy to install,
as it only requires one coupling and a safety guard.
Complete ranges of drive speeds are available and
usually one can be found within a few rev/min off the
required speed.
As twin screw pumps are often selected due to the
process flexibility they offer, they would typically not
be selected for a duty requiring one fixed speed. In
low-speed applications (1000 rev/min) however, it
can still be relevant to use a geared electric motor. For
applications requiring higher speeds (e.g. CIP) a direct
coupled motor (4, 6 or 8 pole) is the common choice
with twin screw pumps.
To handle changing duty conditions or a number of
different duties, it may be necessary to use a frequen-
cy converter (inverter) to obtain correct pump duty
speeds. The frequency converter allows the operator
to change the frequency of the electric motor, there-
by changing pump speed and controlling flow (see
chapter 9).
250
8.0
Pump
Specification
Options

Baseplates
The Alfa Laval ‘standard’ is a folded stainless-steel
design (Fig. 8.2.8a) which is required to be bolted to
the floor (see chapter 12).
In some application areas, such as dairy or brewing, it
is normal practice to hose down pump units and floor-
ings – in these circumstances ball feet can be fitted
to baseplates, which can be a fixed or variable height
and conform to 3A standard (see chapter 12), to raise
baseplate above floor level (Fig. 8.2.8b). Baseplates
can also be designed to meet specific customer
standards when required.
Guards
All rotating machinery should be adequately guarded
and when pumps are supplied complete with a drive,
a guard is fitted over the flexible coupling which links
the pump drive shaft to the output shaft of the electric
motor.
The selection of guard material is important relative to
its working environment. Non-sparking materials such
as aluminium or brass are used with flameproof/explo-
sion proof motors in hazardous areas. For non-hazard-
ous applications stainless steel is generally used.
Shrouds
As an alternative to the guard a stainless-steel shroud
covering both flexible coupling and complete electric
motor is available. The purpose of the shroud is to pro-
tect the motor during washdown of the process area.
Fig. 8.2.8b DuraCirc circumferential piston pump with shaft guard and
geared motor baseplate with adjustable ball feet
Fig. 8.2.8a DuraCirc circumferential piston pump, with shroud and
geared motor on folded baseplate
251
8.0
Pump
Specification
Options

8.3 Q-doc
Alfa Laval Q-Doc is a complete documentation pack-
age, meeting the needs and demands of customers
within the BioPharmaceutical industry (Fig. 8.3a).
Based on Good Documentation Practice (GDP), Q-doc
documents every aspect from raw material to delivered
equipment. With full transparency of sourcing, produc-
tion, and supply chains it is a simple matter to trace
even the slightest change in material or manufacturing
procedures – even when it comes to spare parts.
Alfa Laval Q-doc comprises conformity declaration on
EU food trace, elastomers and surface finish, material
certificates, relevant test certificates and informa-
tion about necessary Alfa Laval spare parts kits for
standard components. The documentation package
supports a smooth qualification and validation process
and safeguards long-term peace of mind.
Q-doc declarations
• Compliance with Regulation (EC) No.: 1935/2004
• Compliance to EN 10204 type 3.1 (MTR)
• Compliance to the U.S. Food Drug Administration
CFR 21 (non-metallic parts)
• Compliance to the U.S. Pharmacopeia (Elastomers
and Polymers)
• TSE (Transmissible Spongiform Encephalopathy)/
ADI (Animal Derivative Ingredient)
• Surface finish compliance to specification
• Passivation and electro polishing compliance to
specification (if specified)
Availability of the Alfa Laval Q-doc is situated within
the Alfa Laval UltraPure pump range:
Centrifugal pumps: LKH UltraPure, LKH Prime
UltraPure
Positive Displacement pumps: SX UltraPure
The complete Q-doc documentation pack for each
pump and/or service kit can be downloaded by the
user from Alfa Laval’s website, simply by typing in
pump serial number or service kit lot number.
To download a Q-doc go to Alfa Laval FindMyCert.
Fig. 8.3a - Q-doc
8.0
Pump
Specification
Options

8.4 Alfa Laval Condition Monitor
The Alfa Laval CM condition monitor is a quick and
easy battery-operated device, to attach to rotating
equipment and detect any change in the equipment
behaviour; Industry 4.0 technology ready (Fig. 8.4a).
Providing users via Bluetooth radio with easy, safe data
to enable them to optimise their process uptime, assist
in maintenance scheduling and efficiency and reduce
operating costs.
The Alfa Laval CM periodically measures the tri-axial
vibration of the installed unit and the internal tempera-
ture storing 3 months of data for analysis, comparing
it to the original baseline set-up values and pre-set
warning and alarms, which if exceeded provide a visi-
ble indication via its LED and via the users compatible
connected mobile device (Fig. 8.4b).
To add this to your pump configuration in the Alfa Laval
Anytime configurator tool, use the “Condition Monitor”
tab and select the CM Kit. This will add another line to
your quote/order and the kit will be supplied in the box
with the pump.
Fig. 8.4.a Condition Monitor
Fig.8.4.c Condition Monitor on LKH centrifugal pump
Fig. 8.4.b Condition monitor connect - Cloud storage solution
Fig. 8.4.d Condition Monitor on positive displacement pump
253
8.0
Pump
Specification
Options

This chapter describes electric motors,
including information on motor protection,
methods of starting, motors for hazardous
environments and speed control.
254
9.0
Motors

Motors
9.0
255
9.0
Motors

All Alfa Laval pump ranges can be fitted with AC type
Totally Enclosed Fan Cooled (TEFC) squirrel cage,
three phase electric motors complying with various
international standards and regulations such as IEC,
CENELEC, VDE, DIN, BS and UL.
Electric motors supplied in the US are generally to
NEMA (National Electrical Manufacturers Association)
standard.
An AC (alternating current) motor is a type of electric
motor that converts electrical energy into mechanical
energy by utilizing the principles of electromagnetic
induction. The standard design of an AC motor con-
sists of several key components, each playing a crucial
role in its operation (see Fig. 9a).
Fig. 9a Electrical hazard
Fig. 9a - exploded view of a TEFC Induction motor
W
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P
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Cód:
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Doubts? Contact us! www.weg.net
Internal
non-drive end
bearing cap
Fan cover
Terminal box cover
Fan
External
non-drive end
bearing cap
Non-drive
endshield
Drain
Wound Stator
Seal
Rotor
Key
Frame
Terminal box
adaptor device
Terminal box
Shaft
Drive end
bearing
Internal drive
end bearing cap
External drive end
bearing cap
Drive
endshield
Grease nipple
Nameplate
Non-drive
end bearing
256
9.0
Motors

1. Stator
The stationary part of the motor is primarily re-
sponsible for generating a rotating magnetic field.
It consists of a laminated core made of high-per-
meability magnetic material, typically stacked thin
steel sheets. The core is designed to reduce eddy
current losses and improve the efficiency of the
motor. The stator also houses the stator windings,
which are typically made of copper wire and are
wound around the core in specific configurations.
2. Rotor
The rotor is the rotating part of the motor and is
subjected to the rotating magnetic field generated
by the stator. It is typically composed of a laminat-
ed iron core with conductive bars or coils embed-
ded within it. The rotor windings are connected to a
metal (iron) core, allowing the flow of current. When
the stator’s magnetic field interacts with the rotor’s
conductive elements, it induces an electromagnetic
field that causes the rotor to rotate.
3. Bearings
AC motors incorporate bearings to support and fa-
cilitate smooth rotation of the rotor. These bearings
are typically ball bearings or roller bearings and are
positioned at each end of the motor’s shaft. They
provide low friction and support the rotor’s weight,
ensuring stable and efficient operation.
4. Shaft
The motor shaft connects the rotor to the exter-
nal load or the driven equipment. It transfers the
rotational motion generated by the rotor to the
mechanical system being powered by the motor.
The shaft is usually made of hardened steel and is
carefully balanced to minimize vibration and ensure
smooth operation.
5. Frame
The motor frame encloses and protects the internal
components of the motor. It provides structural
integrity and houses the stator, rotor, bearings, and
other internal parts. The frame is typically made of
cast iron, aluminium, or steel, depending on the
motor’s size, and intended application.
6. Cooling System
AC motors generate heat during operation, and it is
important to dissipate this heat to maintain optimal
performance and prevent overheating. AC motors
employ various cooling methods such as forced air
cooling, liquid cooling, or a combination of both.
Cooling fins, fans, or cooling jackets may be inte-
grated into the motor’s design to ensure efficient
heat dissipation.
7. Terminal Box
The terminal box is a housing located on the
exterior of the motor and contains the electrical
connections. It provides a convenient access point
for connecting power supply cables to the motor
windings. The terminal box often includes termi-
nals, such as screw terminals or terminal blocks,
for connecting the motor to the appropriate power
source.
8. Protective Devices
To safeguard the motor from electrical faults or
abnormal operating conditions, protective devices
such as thermal overload relays or circuit breakers
are often incorporated. These devices monitor
motor parameters such as current, temperature,
and voltage, and can interrupt the power supply to
the motor in case of an overload or fault.
The motor is constructed as follows:
These are the basic components and features found
in the standard design of an AC motor. The specific
design and characteristics may vary depending on the
motor’s size, power rating, and intended application,
but the fundamental principles remain the same.
257
9.0
Motors

9.1 Output Power
The output power of an AC motor is related to the
active power, also known as the real power or true
power, consumed by the motor. The rated output
power of a motor refers to the maximum power it is
designed to deliver continuously under normal operat-
ing conditions.
The rated output power is typically specified by the
motor manufacturer and represents the motor’s
capacity or capability to perform work. It is usually
expressed in units of watts (W), kilowatts (kW) or
horsepower (HP).
In an ideal scenario where the motor operates at unity
power factor (PF = 1), the active power is equal to the
apparent power. In this case, the output power would
be equal to the apparent power demanded by the
motor from the power source.
However, in practical situations, the power factor (PF)
of an AC motor is often less than 1 due to the pres-
ence of reactive power. Reactive power arises from
the inductive or capacitive components of the motor’s
circuit, which can cause the current to lead or lag
behind the voltage.
The power factor (PF) is defined as the ratio of active
power (P) to apparent power (S):
PF = P/S
As the power factor decreases (i.e., PF 1), the ap-
parent power increases in relation to the active power.
This means that for the same output power, a motor
with a lower power factor will demand more apparent
power from the power source.
To calculate the output power of a motor, you need to
consider the power factor. The output power (P_out)
can be determined using the following formula:
P_out = P × PF
Where:
P_out = Output power (watts or kilowatts)
P = Active power (watts or kilowatts)
PF = Power factor (between 0 and 1)
Therefore, the output power of an AC motor is directly
dependent on the active power consumed by the
motor, which, in turn, is influenced by the power factor.
By optimizing the power factor of the motor, you can
maximize its efficiency and ensure that the motor oper-
ates closer to its rated output power.
The table below shows output power that is specified
in standard ratings.
Frequency Output Power in kW
50/60 Hz 0.37 0.55 0.75 1.1 1.5 2.2 3 4 5.5 7.5
11 15 18.5 22 30 37 45 55 75 90
Table 9.1a (IEC motors)
Frequency Output Power in HP
60 Hz 0.5 0.75 1 1.5 2 3 5 7.5 10
15 20 25 30 40 50 60 75 100
Table 9.1b (Nema motors)
258
9.0
Motors

9.2 Rated Speed
The rated speed of an electric motor refers to the
speed at which the motor is designed to operate under
normal operating conditions while delivering its rated
output power. The rated speed is typically specified by
the motor manufacturer and is an important parameter
when selecting a motor for a specific application. The
description of rated speed differs for asynchronous
(induction) motors and synchronous motors, so let us
explore each of them:
Asynchronous (Induction) Motors
Asynchronous motors are the most commonly used
type of AC motors. They operate based on the princi-
ple of electromagnetic induction. In an asynchronous
motor, the rotor rotates at a speed slightly lower than
the synchronous speed, which is determined by the
frequency of the power supply and the number of
poles in the motor.
The rated speed of an asynchronous motor is specified
as the synchronous speed (Ns) divided by a slip factor
(s). The slip is the difference between the synchronous
speed and the actual rotor speed, expressed as a
percentage or a decimal. The rated speed (N_rated)
can be calculated using the formula:
N_rated = Ns * (1 - s)
Example: 4pole - induction motor
Ns = 1500 rpm
s = 4%
N_rated = 1500 * (1 – 0.04) = 1440 rpm
Typically, the slip at the rated load is small, resulting
in a rated speed close to the synchronous speed.
However, the actual speed of an asynchronous motor
varies with the load and may be lower than the rated
speed under heavy loads.
To calculate the slip factor (s) we can use the following
formula:
s = (Ns – N) / Ns
s - slip factor
Ns - synchronous speed
N – rotor speed
259
9.0
Motors

Synchronous Motors
Synchronous motors are designed to operate at a
speed that is perfectly synchronized with the frequen-
cy of the power supply. The rotor of a synchronous
motor rotates at the same speed as the rotating
magnetic field generated by the stator. This synchro-
nous speed (Ns) is determined by the frequency of the
power supply and the number of poles in the motor.
The rated speed of a synchronous motor is equal to
the synchronous speed (Ns) since the rotor always
moves at this speed. In other words, the rated speed
is the actual speed of the motor at its rated output
power. Synchronous motors are often used in applica-
tions that require precise speed control or applications
where a constant speed is essential.
It is important to note that synchronous motors require
a separate excitation source to maintain synchroni-
zation with the power supply frequency. This can be
achieved through permanent magnets or by providing
DC excitation to the rotor windings.
In summary, the rated speed of an asynchronous
motor is specified as the synchronous speed divided
by a slip factor, while the rated speed of a synchronous
motor is equal to the synchronous speed itself. The
rated speed is an important parameter that helps
determine the motor’s performance characteristics
and suitability for a particular application.
An example between synchronous speed, rated
speed, frequency and poles is shown in the table
below.
No. poles 2 4 6 8 12
No. pairs of poles 1 2 3 4 6
Synchronous speed at 50 Hz - rev/min 3000 1500 1000 750 500
Rated speed at 50 Hz - rev/min 2880 1440 960 720 480
Synchronous speed at 60 Hz - rev/min 3600 1800 1200 900 720
Rated speed at 60 Hz - rev/min 3460 1720 1150 860 690
Table 9.2a
260
9.0
Motors

9.3 Voltage
Three-phase motors
For three-phase motors operating at 50 or 60 Hz fre-
quency, the common voltage ratings used worldwide
are as follows:
208 V
This voltage rating is commonly used in North
America, particularly in commercial and residential
settings.
It is suitable for smaller motors with power ratings
typically ranging from a few hundred watts to several
kilowatts.
The voltage is distributed across the three phases,
resulting in a line-to-line voltage of 208 V and a line-to-
neutral voltage of approximately 120 V.
230 V
This voltage rating is prevalent in various regions,
including parts of North America, Europe, and Asia.
It is commonly used for smaller motors in residential,
commercial, and light industrial applications.
380 V
The voltage rating of 380 V is commonly used in sever-
al regions, including parts of Asia (China), Europe, and
Africa.
It is often employed in industrial and commercial
applications.
400 V
This voltage rating is widely used in Europe, Asia, and
other regions as a standard for industrial applications.
It is common for motors, with up to several hundred
kilowatts in power.
460 V
This voltage rating is predominantly used in North
America for industrial applications.
575 V
This voltage rating is primarily used in North America,
particularly in industrial settings.
Alfa Laval supplied motors at 400 or 460 V will gener-
ally operate satisfactorily with voltage variations of ±
10% from the rated voltage as per IEC 60038.
261
9.0
Motors

9.4 Cooling
Motor cooling
Motor cooling is specified by means of the letters IC
(International Cooling) in accordance with standards.
The most common is IC411 (Totally Enclosed Fan
Cooled - TEFC) where an externally mounted fan cools
the motor.
Some common methods of cooling for motors are
shown below:
Code Arrangement
IC411 Totally Enclosed Fan Cooled (TEFC) – motor cooled by an externally mounted fan
IC410 Totally Enclosed Non-Ventilated (TENV) – self cooling, no externally mounted fan
IC418 Totally Enclosed Air Over Motor (TEAOM) – motor cooled by airstream
IC416 Totally Enclosed Blower Cooled (TEBC) – motor cooled by an independent fan
Table 9.4a
9.0
Motors

9.5 Insulation and Thermal Rating
Insulation
Insulation plays a critical role in ensuring the safe and
reliable operation of the motor. It helps to protect the
motor windings and other internal components from
electrical breakdown and thermal damage. The insu-
lation materials and thermal rating of an AC motor are
important considerations in motor design and selec-
tion. Here are some key details:
Insulation Classes
AC motor insulation systems are categorized into
different insulation classes based on their thermal
capabilities and temperature limits.
The insulation classes are standardized and designa-
ted by letters, such as Class A, Class B, Class F, and
Class H, among others.
Each insulation class has a specific maximum allowa-
ble operating temperature, which indicates the maxi-
mum temperature the insulation system can withstand
without significant degradation or loss of insulation
properties.
Thermal Rating
The thermal rating of an AC motor specifies its max-
imum allowable operating temperature based on its
insulation class.
The thermal rating is typically expressed as a temper-
ature rise above the ambient temperature, measured
at a specific point on the motor, such as the winding or
the stator.
For example, a motor with a Class F insulation system
may have a thermal rating of 105° C, meaning the
maximum allowable temperature rise is 105° C above
the ambient temperature.
Temperature Monitoring and Protection
AC motors often incorporate temperature monitoring
devices, such as thermistors (PTC) or thermostats, to
measure the actual winding temperature.
These temperature sensors provide feedback to the
motor control system, allowing for temperature-based
protection and control strategies.
If the motor temperature exceeds safe limits, protective
measures like thermal overload relays or motor protec-
tive relays may be activated to shut down or protect
the motor from damage.
It is important to select an AC motor with an insula-
tion class and thermal rating that is suitable for the
operating environment and the expected temperature
conditions. Operating the motor within the specified
temperature limits helps ensure the longevity, efficien-
cy, and reliability of the motor’s insulation system and
prevents insulation breakdown or thermal degradation.
Standard Alfa Laval supplied motors will operate satis-
factorily in an ambient temperature range of -20° C
(-4° F) to 40° C (104° F) (Class B temperature rise) and
at altitudes up to 1000 metres above sea level
– Classified as Class F/Temperature Rise B.
Motors supplied with class F insulation system with
class B temperature rise (80° C) (176° F) ensure an
exceptional margin of safety and longer life even in
abnormal operating conditions such as withstanding
ambient temperatures up to 55° C (131° F) or 10%
overload or adverse supply systems. Motors operating
in ambient temperatures higher than 55° C (131° F) will
have class H insulation. Some de-rating of the motor
may be necessary for high ambient temperatures and
high altitude.
263
9.0
Motors

Designation 1st
Digit 2nd
Digit
Protection against contact and ingress of foreign
bodies
Protection against water
IP44 Protection against contact with live or moving parts
by tools, wires, or other objects of thickness greater
than 1 mm (about 0.04 in). Protection against the
ingress of solid foreign bodies with a diameter
greater than 1 mm
Water splashed against the motor from any direc-
tion shall have no harmful effect
IP54 Complete protection against contact with live or
moving parts inside the enclosure. Protection
against harmful deposits of dust. The ingress of
dust is not totally prevented, but dust cannot enter
in an amount sufficient to interfere with satisfactory
operation of the machine
Water splashed against the motor from any direc-
tion shall have no harmful effect
IP55 Water projected by a nozzle against the motor from
any direction shall have no harmful effect
IP56 Motor protected against conditions on a ship’s deck
or powerful water jets
IP65 No ingress of dust Water projected by a nozzle against the motor from
any direction shall have no harmful effect
IP66 No ingress of dust - “Dust-tight” Motor protected against high pressure and powerful
water jets/sprays
Table 9.6a
9.6 Protection
The degree of motor protection is specified by means
of the letters IP (International Protection) in accordance
with standards. These state the method of determining
degrees of ingress protection for both dust and water.
The letters IP are followed by two digits, the first of
which specifies the protection against contact and in-
gress of foreign bodies and the second digit specifies
the protection against water.
Table showing degrees of protection is shown below:
Alfa Laval offers protection levels of IP55 as standard
within the hygienic industries with an option for the
improved IP66 when requested/conditions demand
– Please contact Alfa Laval for more information.
9.6.1 Basic UL/CSA/Nema Enclosure Types
Type 3
An enclosure which is intended for outdoor use
primarily to provide a degree of protection against
windblown dust, rain, and damage from external ice
formation.
Type 3R
primarily to provide a degree of protection against
falling rain and damage from external ice formation.
Type 3S
primarily to provide a degree of protection against rain,
sleet, windblown dust, and to provide for operation of
external mechanisms when ice laden.
Type 4
An enclosure which is intended for indoor or outdoor
use primarily to provide a degree of protection against
windblown rain and dust, splashing water, hose direct-
ed water and damage from external ice formation.
Type 4X
corrosion, windblown rain and dust, splashing water,
hose directed water and damage from external ice
formation.
264
9.0
Motors

Type 6
falling dirt, hose directed water, the entry of water
during occasional temporary submersion at a specified
depth and damage from external ice formation.
Type 6P
use to primarily provide a degree of protection against
falling dirt, hose directed water and the entry of water
during prolonged submersion at a specified depth and
damage from external ice formation.
Tropic Proof Treatment
Motors operating in tropical climates are invariably
subjected to hot, humid, and wet conditions, which
will produce considerable amounts of condensation
on internal surfaces. Condensation occurs when the
surface temperature of the motor is lower than the
dew-point temperature of the ambient air. To overcome
this, motors can be supplied with special tropic proof
treatment. Failure to include this treatment and the
resulting corrosion can cause irreparable damage to
stator windings and moving parts.
If required, please contact Alfa Laval for more
information.
Anti-Condensation Heaters
Where the motor is to be left standing for long periods
of time in damp conditions it is recommended that
anti-condensation heaters are fitted and energised to
prevent condensation forming in the motor enclosure.
These heaters are normally 110 V or 220 V.
If required, please contact Alfa Laval for more
information.
Thermistors
(PTC – Positive Temperature Coefficient)
To protect the motor windings from overload due to
hot temperature, motors can be fitted with thermistors,
which are temperature-dependent semi-conductor
devices embedded in the motor windings. Where
motors can be allowed to operate at slow speed, i.e.,
being used with a frequency converter (see section
9.9), it is normal to fit thermistors to prevent the motor
from overloading or to insufficient cooling from the
motor fan.
Thermostats
Mechanical or electronic devices designed to monitor
and control temperature in a system. They typically
consist of a bimetallic strip and operates based on the
principle of thermal expansion. The bimetallic strips are
installed within the motor windings or in close prox-
imity to them. The bimetallic strip is composed of two
different metals bonded together that have different
coefficients of thermal expansion. As the motor current
flows through the windings, they generate heat due
to the electrical resistance. The bimetallic strip in the
motor thermal protector is designed to bend with
temperature changes. As the motor temperature rises
above a certain threshold, the bimetallic strip bends,
tripping a switch and interrupting the power supply to
the motor. This action protects the motor from further
heat build-up and potential damage. Once the motor
cools down, the bimetallic strip returns to its original
position, allowing the motor to be restarted.
Note:
All motors supplied by Alfa Laval come with thermis-
tors or thermostats (US) as standard to allow
frequency converter operation.
265
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9.7 Methods of Starting
Choice of Starting Method
The choice of starting method depends on factors
such as motor size, application requirements, and
available power supply. Here are the main methods of
starting an induction motor:
Direct-On-Line (DOL) Starting
This is the simplest and most common method of
starting induction motors. In DOL starting, the motor
is directly connected to the power supply, typically
through a contactor or a circuit breaker. When the
power is switched on, the motor receives the full
supply voltage, causing it to start abruptly. DOL
starting is suitable for small- to medium-sized
motors but can cause high starting currents and
mechanical stress.
Motors fitted to centrifugal and liquid ring pumps are
normally directly started, as the moment of inertia of
the motor is low due to pump design and the fluids
being pumped having low viscosities. In this case the
starting time with high starting current is incredibly low
and it can consequently be ignored.
Star-Delta (Wye-Delta) Starting
Involves initially connecting the motor’s stator windings
in a star (wye) configuration during the starting period,
which reduces the voltage across each winding. Once
the motor reaches a predetermined speed, the wind-
ings are then switched to a delta (mesh) configuration
for normal operation, where the voltage across each
winding is higher. Star-delta starting reduces the start-
ing current and torque, limiting the stress on the motor
and the power supply (Fig. 9.7a).
If pumping viscous fluids or using a positive displace-
ment pump, the starting time with the high starting
current is longer and therefore requires some restric-
tion of the starting current by using the star-delta
method.
Fig. 9.7a Connection of three-phase single speed motor
∆-connection
L1
W2 U1
U2
L2
V1
V2
L3
W1
L1
W2
U1
U2
L2
V1
V2
L3
W1
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Auto-Transformer Starting
This method is similar to star-delta starting and is
used for larger motors with high starting currents. An
auto-transformer is connected between the power
supply and the motor’s stator windings. Initially, the
motor is connected to taps on the auto-transformer
that provide a reduced voltage. As the motor acceler-
ates, the taps are switched to provide a higher voltage.
Auto-transformer starting helps reduce starting current
and torque while providing a smooth acceleration.
Soft Starting
Soft starting methods are designed to gradually
increase the voltage supplied to the motor during start-
up, thus reducing the starting current and mechanical
stress. This can be achieved using devices such as
auto-transformers, solid-state soft starters, or varia-
ble frequency drives (VFDs). Soft starting minimizes
voltage dips in the power supply and enables con-
trolled acceleration of the motor. In many cases the
soft starter saves energy by automatically adapting the
motor voltage continually to the actual requirement.
This is particularly important when the motor runs with
a light load.
Frequency Converter Starting
Frequency converters, also known as variable frequen-
cy drives (VFDs) or inverters, allow precise control of
the motor’s speed and torque. They can be used for
both starting and speed control of induction motors.
VFDs convert the fixed-frequency AC power supply
into variable frequency and voltage output, allowing
smooth acceleration and deceleration of the motor.
Frequency converter starting offers flexibility and ener-
gy savings but is more complex than other methods.
These are the main methods used for starting induc-
tion motors. The choice of method depends on factors
such as motor size, application requirements, energy
efficiency considerations, and cost constraints.
Alfa Laval recommends the use of a qualified electri-
cian to best assess the optimal starting method and to
carry out the required installation/set-up.
Fig. 9.7a Connection of three-phase single speed motor
Y-connection
L1
W2
U1
U2
L2
V1
V2
L3
W1
L1
W2
U1
U2
L2
V1
V2
L3
W1
L1
U1
U2
L2
V1
V2
L3 W1
W2
267
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ATEX
Short for “ATmosphères EXplosibles,” is a European
Union directive that outlines safety requirements for
equipment used in potentially explosive atmospheres.
It aims to protect workers and the environment from
the risks associated with such environments. ATEX
defines specific product categories and motor equip-
ment protection methods to ensure safe operation
in hazardous areas. ATEX classifies equipment into
various categories based on their intended use in
explosive atmospheres. The categories are as follows:
Zones
The degree of hazard varies from extreme to rare.
Hazardous areas are classified into three Zones as
follows:
Zone 0
An explosive gas-air mixture is continuously present
or present for extended periods – No motors may be
used in this zone.
Zone 1
An explosive gas-air mixture is likely to occur in normal
operation.
Zone 2
An explosive gas-air mixture is not likely to occur in
normal operation and if it occurs it will only be present
for a brief time.
To ensure equipment can be safely used in hazardous
areas, its gas group must be known, and its temper-
ature class must be compared with the spontaneous
ignition temperature of the gas mixtures concerned.
By implication, an area that is not
classified Zone 0, 1 or 2 is deemed
to be a non-hazardous or safe area.
Temperature class Ignition temperature for gas/vapour Max. permitted temperature of electrical equipment
T1 up to 450° C (842° F) 450° C (842° F)
T2 300 to 450° C (572 to 842° F) 300° C (572° F)
T3 200 to 300° C (410 to 572° F) 200° C (410° F)
T4 135 to 200° C (275 to 410° F) 135° C (275° F)
T5 100 to 135° C (212 to 275° F) 100° C (212° F)
T6 85 to 100° C (185 to 212° F) 85° C (185° F)
Group I Equipment for coal mines susceptible to methane gas – Alfa Laval does not cover this group
Group II Equipment for explosive atmospheres other than mines i.e., surface industries
IIA
IIB
IIC
Group II is subdivided according to the severity of the environment. IIC is the highest rating.
A motor from one of the higher categories can also be used in a lower category
Table 9.8a
Table 9.8b
9.8 Motors for Hazardous Environments
268
9.0
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Flameproof Enclosure - Ex d
These motors are designated for operation in Zone 1
hazardous areas. The motor enclosure is designed in
such a way that no internal explosion can be transmit-
ted to the explosive atmosphere surrounding the ma-
chine. The enclosure will withstand, without damage,
any pressure levels caused by an internal explosion.
The temperature of the motor’s external enclosure
should not exceed the self-ignition temperature of the
explosive atmosphere of the installation area during
operation. No motor device outside the flameproof
area shall be a potential source of sparks, arcs, or
dangerous overheating.
International standard IEC 60079-1
Suitable for Zones 1 and 2.
Increased Safety Design – Ex e/Ex ec
The design of this motor type prevents the occurrence
of sparks, arcs, or hot spots in service, that could
reach the self-ignition temperature of the surrounding,
potentially explosive atmosphere, in all inner and outer
parts of the machine.
Suitable for Zones 1 and 2.
Non-Sparking Design – Ex ec
These motors are designated for operation in Zone
2 hazardous areas. The motor construction is similar
to standard TEFC motors, but with special attention
to eliminate production of sparks, arcs, or dangerous
surface temperatures.
Suitable for Zone 2 only.
When requiring use of an ATEX approved motor drive,
Alfa Laval offers Zone 1, Ex d, IIB, 2G, and T4 as
standard.
Please contact Alfa Laval for alternative options.
269
9.0
Motors

Class II: Locations where combustible dust is or may
be present in sufficient quantities to cause a fire or
explosion. Class II is further divided into Divisions 1
and 2, similar to Class I.
Class III: Locations where easily ignitable fibers or
flyings are or may be present in sufficient quantities to
cause a fire or explosion. Class III is not divided into
divisions.
Group Classification (NEC)
Within each class, hazardous substances are further
classified into groups based on their properties. The
group classification specifies the type of substance
and its level of hazard. For example:
Group A: Acetylene
Group B: Hydrogen, butadiene, ethylene oxide
Group C: Ethylene, propylene, acrolein
Group D: Propane, gasoline, acetone
When requiring use of an NEC explosion proof ap-
proved motor drive, Alfa Laval offers Class 1, Div 1,
and Group D as standard.
Zone System (CEC)
The Canadian Electrical Code (CEC) also provides a
classification system for hazardous locations, known
as the Zone System. The CEC divides hazardous
locations into zones based on the likelihood and du-
ration of the presence of flammable substances. The
zones are categorized as Zone 0, Zone 1, Zone 2, and
Zone 20, Zone 21, and Zone 22 for gases and dust,
respectively.
In North America, hazardous motors are classified
and regulated by the National Electrical Code (NEC)
and the Canadian Electrical Code (CEC). These codes
provide guidelines for the safe installation and use of
electrical equipment, including motors, in hazardous
locations. The classifications and standards in North
America differ from the ATEX system used in Europe.
Here is an overview of the North American standards
and classifications:
Class and Division System (NEC)
The NEC makes use of a Class and Division system to
classify hazardous locations based on the type of haz-
ardous substance present. It categorizes hazardous
locations into three classes and two divisions:
Class I: Locations where flammable gases, vapours or
liquids are, or may be, present in sufficient quantities to
cause a fire or explosion.
Class I is further divided into Divisions 1 and 2.
• Division 1: Hazardous substances are present
under normal operating conditions or during abnor-
mal situations, such as leaks or equipment failure
• Division 2: Hazardous substances are handled,
processed, or stored, but are not present under
normal operating conditions or during abnormal
situations
9.0
Motors

9.9 Energy Efficient Motors
Motor energy efficiency plays a crucial role in reducing
energy consumption and promoting sustainable prac-
tices in various industrial and commercial applications.
In recent years, governments and regulatory bodies
around the world have introduced minimum energy
efficiency regulations to encourage the use of more
efficient motors. Four widely recognised classification
in this regard are IEC standards such as IE1, IE2, IE3,
IE4 and IE5.
Motor energy efficiency refers to the ability of an elec-
tric motor to convert electrical energy into mechanical
energy with minimal losses. Traditional motors are
known to have significant energy losses due to factors
such as resistive losses, mechanical losses, and stray
losses. These losses result in wasted energy and
increased operating costs.
IE1 (Standard Efficiency Standard)
IE1 is the basic energy efficiency standard for mo-
tors, defined by the International Electrotechnical
Commission (IEC) under IEC 60034-30-1. Motors that
meet the IE1 standard have relatively lower energy
efficiency compared to more advanced motor designs.
However, they are still widely used in applications
where energy efficiency is not a primary concern.
IE2 (High Efficiency Standard)
IE2 is an intermediate energy efficiency standard, also
defined by the IEC under IEC 60034-30-1. Motors
that comply with the IE2 standard offer higher energy
efficiency compared to IE1 motors. These motors are
designed to reduce energy losses and are considered
an improvement over IE1 motors.
IE3 (Premium Efficiency Standard)
IE3 is an international standard for energy-efficient
motors, defined by the IEC under IEC 60034-30-1.
According to this standard, motors must meet specific
efficiency levels to be classified as IE3. IE3 motors
have higher efficiency compared to IE1 and IE2
motors and are considered a significant improvement
in energy performance.
IE4 (Super Premium Efficiency Standard)
IE4 is a more stringent energy efficiency standard
introduced as an extension of the IE3 standard. Also
known as super premium efficiency motors, IE4 mo-
tors have even higher efficiency levels than IE3 motors.
These motors are designed to minimize energy losses
and are typically used in applications where energy
savings are critical.
IE5 (Ultra Premium Efficiency Standard)
IE5 is the highest energy efficiency standard currently
defined by the IEC. IE5 motors offer the highest level of
efficiency among all the standards. These motors are
designed using advanced technologies and materials
to achieve exceptional energy performance and are
typically used in applications where maximum energy
savings and performance are required.
Alfa Laval’s supply of motors are also in accordance
with the Minimum energy Efficiency Regulations
(MEPs) with IE3 as the default efficiency level.
Please contact Alfa laval on alternative requests for
higher efficiency levels such as IE4 or IE5.
9.9.1 Minimum Energy Efficiency Regulations
(MEPs)
To promote the adoption of energy-efficient motors
and reduce overall energy consumption, many coun-
tries have implemented minimum energy efficiency
regulations. These regulations typically specify the
minimum efficiency levels that motors must meet to
271
9.0
Motors

Motor energy efficiency and minimum energy regula-
tions such as IE1, IE2, IE3, and IE4 have transformed
the motor industry by promoting the development and
adoption of more energy-efficient technologies. These
standards have played a vital role in reducing energy
consumption, lowering operating costs, and mitigating
the environmental impact of motor-driven systems. By
adhering to these regulations, industries can contribute
to a more sustainable future while reaping the benefits
of energy and cost savings.
When required to supply motorised pumping units,
Alfa Laval offers a comprehensive range of motors
tailored to meet the diverse needs of customers across
all countries, while adhering to the minimum energy
efficiency requirements set forth by the respective
regulatory bodies.
IEC
60034-30-1
IE1 IE2 IE3 IE4 IE5
NEMA
MG1
Std High Premium
NBR
17094-1
IR2 IR3
GB
18613-2012
GB3 GB2 GB1
GB
18613-2020
GB3 GB2 GB1
Table 9.9.1a Overview on common efficiency grades globally
be legally sold and operated in those regions. The
IE1, IE2, IE3, and IE4 standards are commonly used
as benchmarks in these regulations and are under
constant review and change to further push the most
sustainable offerings in motor energy efficiency.
Benefits of High-Efficiency Motors
Energy Savings: High-efficiency motors significantly
reduce energy consumption, leading to lower operat-
ing costs and decreased carbon emissions.
Cost Savings: Although high-efficiency motors may
have a higher initial cost, the energy savings over
the motor’s lifetime usually outweigh the upfront
investment.
Environmental Impact: Using energy-efficient motors
helps reduce greenhouse gas emissions and contrib-
utes to environmental sustainability.
Enhanced Performance: Efficient motors often offer
improved performance, including better speed control,
reduced noise levels, and increased reliability.
272
9.0
Motors

9.10 Speed Control
The effective speed control of AC electric motors has
long been regarded as an adaptable and economical
means of reducing costs and saving energy.
Multi-Speed
Pole Change (Tapped or Dahlander).
These have a single winding and two speeds in a
ratio of 2:1 and can be supplied for constant torque
or variable torque applications.
PAM (Pole Amplitude Modulation)
Similar to above except that pole variations can be
4/6 or 6/8.
Dual Wound
Motors have two separate windings and can be
supplied for any two speed combinations.
A combination of dual and pole change windings can
give 3 or 4 speeds from one design.
Mechanical Speed Control
In some cases, mechanical speed control methods
can be employed. These typically involve using
adjustable sheaves or pulleys to change the effective
diameter of the pump drive system. By adjusting the
size of the pulleys, the rotational speed of the pump
can be altered. This method is often used in older or
simpler pump systems.
Throttling Control
Throttling involves partially closing a valve or using a
bypass line to restrict the flow of the pumped fluid.
By increasing the resistance to flow, the pump’s
operating point moves to a lower flow rate and
pressure condition. However, throttling control is
generally not an efficient method since it wastes
energy and may cause excessive wear on the pump –
Important not to be used within systems that include
positive displacement pumps as closing the valve
increases the pressure in the PD pump and the entire
system. The pump will continue to work against the
developed pressure until it reaches its maximum
operating pressure, or the relief valve opens. This
increased pressure will put additional strain on the
pump, its components, and the piping system and if
not corrected, leads to failure.
Variable Voltage
Variable voltage control provides a low capital cost
means of varying the motor speed on centrifugal
pumps. This form of speed control requires greater
derating than for converter drives and is best suited
to 4 pole machines of 2:1 speed reduction with close
matching of motor output to absorbed pump load.
These motors are of special design – standard motors
being unsuitable.
Frequency Converter (Inverter)
The use of a frequency converter will allow speed
control of a standard AC motor by adjusting the
frequency, although some derating may be necessary.
Basic frequency converters will permit operation
over a typical speed range of 20:1. With increasing
sophistication such as ‘vector’ control, e.g., field
oriented control utilising closed loop feedback, the
effective speed range can be increased to 1000:1.
For applications using variable torque loads such as
centrifugal pumps, little derating will be required. For
applications using constant torque loads such as
positive displacement pumps, the level of derating
will depend on the speed range required.
273
9.0
Motors

As well as motors being remotely controlled by
frequency converters, electric motors can be made
available with the frequency converter already inte-
grated to the motor. These arrangements have the
advantage of not using any shielded motor cables, as
there are no extra connections between the frequency
converter and motor. Also providing room in a switch
cabinet will not be necessary.
The motor ratings must take into account:
• Increased heating due to the harmonic content of
the inverter waveforms
• Reduced cooling arising from motor speed
reduction
• The power or torque requirements throughout the
entire speed range
• Other limiting factors such as maximum motor
speeds, ambient temperature, altitude etc.
• When using frequency inverters, it is important to
consider the potential impact on power quality.
VFDs can introduce harmonics into the electrical
system, which may require additional measures like
harmonic filters or power conditioning to mitigate
their effects on other connected equipment.
9.0
Motors

9.11 Motor Sizing Values
Values to consider when sizing for a motor
• Shaft power (kW/HP)
• Speed (rpm)
• Torque (Nm/(Ib ft))
Metric units
Power, speed and torque:
M = P * 9550 / n
Where:
P = Power (kW) M = Torque
Re-arrange for torque:
M = P * 9550 / n
This arrangement shows how speed and power impacts on torque:
P = Power (kW) M = Torque (Nm) n = Speed (rpm)
Imperial US units
Power, speed and torque
M = P * 5252 / n
Where:
P = Power (hp) M = Torque (lb ft) n = Speed (rpm)
Re-arrange for torque
M = P * 5252 / n
This arrangement shows how speed and power impacts on torque:
P = Power (hp) M = Torque (lb ft) n = Speed (rpm)
These 3 values have direct correlation that can be
seen by below formula.
9.11.1 Torque
The main consideration for selecting an electric motor
is torque - not power.
Running a motor over the rated torque output will
cause increased current flow which in most cases will
cause the inverter safety features to stop the motor but
could lead to permanent damage to the motor wind-
ings due to over-heating.
When it comes to the type of pump technology, a
positive displacement pump is considered a constant
torque application where a change in duty does not
automatically correlate to a reduced torque require-
ment, therefore it is imperative the motor torque output
covers the complete adjustment range of required duty
points. Centrifugal pumps have a torque characteristic
curve which increases in a quadratic function, which
favours operation at low speeds as per the affinity laws
but dramatically increases when increasing operation
past the original selection point (see chapter 7 for more
details).
Alfa Laval pumps can operate over speed ranges;
therefore, consideration needs to be made to the
impact the variable speeds have on the torque output
of the motor and the varying power requirements of
the pump at the different duty point to ensure sufficient
motor power and torque is available over the full speed
range.
275
9.0
Motors

9.11.2 Speed/Frequency
Frequency correlates directly to the motor speed and
normally using a variable frequency drive or inverter.
• Decreasing frequency = Decreasing speed
• Increasing frequency = Increasing speed
• All motors supplied with Alfa Laval pumps are suit-
able for frequency inverter use
• Standard motor offering insulation class F/
Temperature rise B (80 °Kelvin)
• All applications involving operating speeds under
5Hz, please contact Alfa Laval Technical Support
9.11.3 Torque/Frequency
An electric motor in theory, will generate constant
torque when frequency is reduced below rated value
(50/60 Hz); This is handled by a Variable Frequency
Drive (VFD) also known as an Inverter (see Fig. 9.11.3a).
A reduction of speed 50 Hz does not result in an
increased torque, as is the case with adjustable gear
units, but rather to a reduction in power. In this case,
the current remains constant for a constant torque and
the voltage reduces with the frequency.
The condition V/F = constant can maximally only be
realised by the frequency inverter up to the nominal
operating point. A further voltage increase above that
of the mains voltage is technically impossible.
Physical factors can impact the torque output of the
motor when speed is decreased, preventing constant
torque.
For example, in self-cooled motors the torque output
decreases as the motor speed reduces. This is caused
by the reduced fan speed leading to reduced motor
cooling causing an increase in motor temperature and
therefore reduced power/torque rated output.
The most common supply frequencies are 50 Hz or 60 Hz
4–pole 6–pole 8–pole 4–pole 6–pole 8–pole
50 Hz 1500 rpm 1000 rpm 750 rpm 60 Hz 1800 rpm 1200 rpm 900 rpm
Physical conditions for constant torque:
M = constant → Φ = constant → U/f = constant
Torque Magnetic flux Voltage/Frequency
Fig. 9.11.3a Voltage to frequency for constant torque
400 V
230 V
0 50 Hz
276
9.0
Motors

With a self-cooled (TEFC) motor on a supply frequency
of 50 Hz, there is a constant torque between 50 - 25
Hz (50% or 2:1) meaning no derating in torque output.
Below 25 Hz, the torque output is derated due to the
slower running speed of the integrated fan, in order
to dissipate the additional heat generated (see Fig.
9.11.3b).
1.05
1.00
0.95
0.90
0.85
0.80
0.75
0.70
0.65
0.60
0.55
0.50
0.45
0.40
0 0.1
A = Slower the speed, the greater the torque derates
B = Constant Torque Range (No derating)
C = Constant flux. Constant V/f. 50 Hz Supply
D = Note:
1.0 represents 100%
Frequency output: 50 or 60 Hz
0.5 would represent 50%; 25 or 30 Hz
E = 25 Hz
F = 50 Hz
A
D
B
C
E F
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9
1.0
Torque derating for self cooling motors
[f/fn] - Operating frequency (p.u.)
[T
R
]
—
Torque
derating
factor
(p.u.)
2.0
1.1 2.1
Fig. 9.11.3b Above shows the relationship of torque to frequency
277
9.0
Motors

This results in 100% torque decreasing to 5 Hz (See
Fig. 9.11.3c).
TEBC units can also be used to help optimise motor
selections where duty points are below the 2:1 motor
turn-down and require a larger motor to meet torque
requirements after derating.
To counter torque derating at reduced speeds, the
following two options can be considered:
1. Forced blower cooled motors (TEBC) are equipped
with a separate fan driven by a separate motor
thereby ensuring 100% airflow regardless of motor
running speed and no derating is required due to
increase motor temperature.
1.05
1.00
0.95
0.90
0.85
0.80
0.75
0.70
0.65
0.60
0.55
0.50
0.45
0.40
0 0.1
A = Constant Torque Range (No derating)
B = Here we can see full torque from 1.0 (50/60 Hz)
down to 0.1 with forced ventilation keeping
the motor cool
C = Forced ventilation. 50 Hz Supply
D = Note:
1.0 represents 100%
E = 5-50 Hz
A
D
B
C
E
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9
1.0
Torque derating for TEBC motors
[T/Tn]
-
Torque
derating
factor
(p.u.)
2.0
1.1 2.1
Fig. 9.11.3c Constant torque graph for TEBC motor
278
9.0
Motors

2. Increased motor size (see Fig. 9.11.3d). Increasing
motor size is the alternative solution. With this,
the motor is operated at a reduced load. Therefore,
there is less power loss and an additional increased
thermal reserve due to increased size of the motor.
Above the nominal frequency the available torque re-
duces, as the voltage is no longer increasing at higher
frequencies (see Fig. 9.11.3a) the magnetic flux reduc-
es. This range is known as the field weakening range.
A further increase in frequency in the field weakening
range therefore results in a torque reduction (See Fig.
9.11.3e).
1.05
1.00
0.95
0.90
0.85
0.80
0.75
0.70
0.65
0.60
0.55
0.50
0.45
0.40
0 0.1
A = Constant Torque
B = Torque derating
Here we can see full torque from
1.0 (50/60 Hz) down to 0.1 with forced
ventilation keeping the motor cool
C = Forced flux. Constant V/f. 50 Hz Supply
D = Note:
1.0 represents 100%
0.5 would represent 50%; 25 or 30 Hz
E = 50 Hz
F = 50 Hz
A
D
B
C
E F
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9
1.0
Torque derating for self cooling motors
[T
R
]
-
Torque
derating
factor
(p.u.)
2.0
1.1 2.1
Fig.9.11.3d Range of IEC motor frame sizes
Fig. 9.11.3e - Constant torque graph for TEFC motor
279
9.0
Motors

Example - Frequency at 70 Hz
In applications where running speed will be above
supply frequency (50/60 Hz), motor torque will auto-
matically be derated due to limitation available power/
voltage.
Motor changes from constant torque to constant
power, therefore as speed increases, available torque
reduces.
The torque reduces according to the relationship
M AB / M NOM = F NOM / F AB
M = Torque
F = Frequency
M70 Hz =
FNOM
FAB
50 Hz
70 Hz
* MNOM = * MNOM = 71% * MNOM
280
9.0
Motors

Note:
Alfa laval pump frequency range recommendations:
Centrifugal pumps
Centrifugal pumps do not have any requirement for
TEBC motors due to the operational principle of cen-
trifugal force and the affinity laws, rendering the pump
technology as variable torque machines.
Operating speeds down to 50% of the set frequency
(50 or 60 Hz) is possible when adjusting an existing
pump to new duty point is required.
25-60 Hz on 50 Hz motor
30-60 Hz on 60 Hz motor
Alfa Laval recommends for optimal selection all cen-
trifugal pumps be sized as close to the best operating
point as duty conditions allow which typically keeps
closer.
Positive displacement pumps
Positive displacement pumps are designed to work
within specific frequency ranges, ensuring optimal per-
formance and longevity due to the operational principle
of displacing fluid in fixed volumetric rotation, renders
this pump technology as constant torque machines.
The frequency range depends on the pump’s design,
size, and intended application.
Alfa Laval recommends consideration in using TEBC
(Force Blower Fan) on positive displacement pumps
when motor frequency is below 20 Hz to offset the
torque reduction and optimise efficiency and sustaina-
bility (duty dependent).
Alfa Laval recommends the use of TEBC (Force Blower
Fan) on positive displacement pumps when motor
frequency is below 10 Hz to offset the torque reduction
(duty dependent).
• Self-cooled motors (TEFC) = 10 - 60 Hz
(consider TEBC between 10-20 Hz operation)
• Forced blower cooled motors (TEBC) = 5 - 60 Hz
For speeds above set frequency, please consult with
Alfa Laval to discuss further as this is very dependent
on pump technology and intended applications.
281
9.0
Motors

282
10
Cleaning
Guidelines
This chapter provides cleaning guidelines
for use in processes utilising CIP (Clean-
In-Place) systems. Interpretations of clean-
liness are given and explanations of the
cleaning cycle.
10.1 CIP (Clean-In-Place)
Clean-In-Place (CIP) is a commonly established clean-
ing method in manufacturing operations associated
within hygienic applications, such as Food Beverage,
Dairy, Home Personal Care, Pharmaceutical
Biotechnology. CIP is designed to remove residual
product and biofilms from processing lines and equip-
ment using turbulent cleaning fluid, without the need to
dismantle the equipment.
The following recommendations offer advice on how to
maximise the CIP (Clean-In-Place) efficiency of the Alfa
Laval ranges of centrifugal and positive displacement
pumps. The guidelines incorporate references to inter-
nationally recognised cleaning detergents, velocities,
temperatures, and pressures used to clean other types
of flow equipment, such as valves and fittings, but
have been specifically prepared to maximise the CIP
effectiveness of our pumps.

283
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Cleaning
Guidelines
Cleaning Guidelines
10

284
10
Cleaning
Guidelines
Positive displacement pumps such as RLP or CPP
are rarely used as the supply pump for CIP fluids.
Centrifugal pumps are generally used during CIP for
each phase of the cleaning cycle. In addition, the intro-
duction of the Twin Screw (TS) pump, within hygienic
industries, has increased flexibility in providing one
pump for process media plus the use as a CIP liquid
supply pump and possibility of performing CIP liquid
return cycles.
For the majority of CIP cycles, it is recommended that
a differential pressure of 2-3 bar is developed across
any pump in a system not being utilised as CIP supply
unit to promote efficient cleaning, whilst it is rotating at
its normal operating speed. In many cases a valve is
employed in the discharge line of the system to create
the differential pressure across the pump(s) and a
by-pass loop installed around said pump(s) to divert
any excess of CIP liquid that the pump is unable to
transfer. The valve(s) setting may be fluctuated during
the CIP cycle to promote pressure/flow variations that
may enhance the cleaning process.
During the CIP cycle there must always be sufficient
flow of cleaning fluid being delivered by the CIP pump
to make sure that the centrifugal or positive displace-
ment pump(s) are neither starved of liquid at the inlet
due to own flow capability, or over pressurised at inlet
due to its tendency to act as a restriction if it is unable
to transfer the full flow of the fluid being delivered.
The perception of the word ‘Clean’ will vary from
customer to customer and process to process. The
four most common interpretations of ‘Clean’ are given
below:
1. Physical Cleanliness
This is the removal of all visible dirt or contamination
from a surface. This level of cleanliness is usually veri-
fied by a visual test only.
2. Chemical Cleanliness
This is defined as the removal of all visible dirt or
contamination as well as microscopic residues, which
are detectable by either taste or smell but not by the
naked eye.
3. Bacteriological Cleanliness
This can only be achieved with the use of a disinfect-
ant that will kill all pathogenic bacteria and the majority
of other bacteria.
4. Sterility
This is the destruction of all known micro-organisms.
The following recommendations for CIP will
address the first three definitions.
In most installations it is important to ensure the
maximum recovery of pumped product residues from
the production line at the end of each production run.
Where this is a requirement, consideration should be
given to mounting pumps such as the RLP (Rotary
Lobe Pump) or Circumferential Piston Pump (CPP)
with ports in the vertical plane to maximise drainability.
This will minimise any product loss, ease the cleaning
of the system and reduce the requirement to dispose
or recycle the wash from the initial cleaning cycles. By
maximising the recovery of product from the system
both the efficiency of the production and cleaning
processes will be increased.

285
10
Cleaning
Guidelines
Internationally accepted protocol for CIP suggests that
during all phases of the CIP cycle a pipeline velocity
of between 1.5 m/sec and 3.0 m/sec is required.
Velocities within this range have proven to provide
effective cleaning of Alfa Laval pumps, although as a
rule, the higher the velocity the greater the cleaning
effect.
Generally, the most effective cleaning
processes incorporate five stages:
1. An initial rinse of clean, cold water (Pre-rinse)
2. Rinsing with an alkaline detergent (Caustic wash)
3. Intermediate rinse with cold water
4. Rinsing with an acidic disinfectant (Acid wash)
5. Final rinse with clean cold water
The cycle times, temperatures, cleaning mediums and
concentrations of the detergents used will all influence
the effectiveness of the cleaning cycle and care must
be taken when defining these to ensure that they
are suitable for use with the product being pumped.
Of equal importance is the chemical compatibility
between the cleaning detergents and the product
wetted materials in the pump head. It is also crucial
to ensure for pumps, that the maximum temperature
profile is more than the intended CIP cycles(s) range.
Consideration should also be given to the disposal
or recycling of used cleaning liquids and the potential
requirement for handling concentrated detergents.
Specialist suppliers should make the final selection of
cleaning detergents/disinfectants.
Within these guidelines a typical cleaning
cycle would be as follows:
1. Rinse with clean water (potable plant, deionized
water) at ambient temperature to remove any
remaining residue. 10-15 minutes are usually suffi‑
cient, but this will depend on the condition and
volume of the residue to be removed.
This is a very important step to monitor as a well-
executed pre-rinse will ensure the rest of the
wash cycle is predictable and repeatable.
2. Rinse with an alkaline detergent, typically a 2.5%
solution of Caustic Soda (NaOH) at between 70° C
to 95° C (158° F to 203° F) for a period of 20-30
minutes would be used. It is common to add a
wetting agent (surfactant) to lower the surface ten-
sion of the detergent to aid its cleansing ability.
This phase of the cleaning cycle should dissolve
and remove organic matter such as fats and
proteins.
3. Intermediate rinse with clean water at ambient
temperature for a period of 5-10 minutes. This
phase should remove any residual detergents.
4. Rinse with an acidic disinfectant, typically a 2.5%
solution of Nitric Acid (HNO3) at ambient tempera‑
ture for a period of 10-15 minutes would be used.
This phase of the cleaning cycle should remove
proteins, mineral salts, lime, and other deposits.
5. Final rinse with clean water at ambient temperature
for a period of 10-15 minutes or until all traces of the
cleaning fluid have been removed.
Note:
In many systems, the final rinse water may be recov-
ered and reused as the pre-rinse solution for the next
cleaning cycle. The residual heat and chemicals it
retains from the final rinse will help make the next pre-
rinse more effective and economical.
During the CIP cycles it is important that the required
concentration of cleaning detergents is maintained
consistently. A significant increase in concentration
could cause damage to pumps and other components
in the system. A significant decrease in concentra-
tion could impact the detergents cleaning efficiency.
A facility for monitoring and adjusting the detergent
concentration should be considered.

286
10
Cleaning
Guidelines
Cautionary Notes:
1. Pumps and other equipment installed in CIP sys‑
tems have components within them that will expand
and contract at different rates. Care should be
taken not to subject them to rapid temperature
cycling.
2. Products containing particulate such as fibre and
seeds have to be evaluated carefully and on an
individual basis, as the nature of these will provide
an increased cleaning challenge. These types of
products may typically require increased cleaning
cycle times and/or increased velocities and pres‑
sures during the cleaning cycle.
3. CIP detergent liquids and the elevated temperatures
typically used for CIP processes can cause a
potential health risk. Always adhere to site Health
and Safety regulations.
4. Always store and dispose of cleaning agents in
accordance with site Health and Safety regulations.
After CIP cleaning an additional Sterilisation-In-Place
process (SIP) may be required when highly sensitive
products are handled, inactivating any micro-organ-
isms which might be still present in the pump after CIP
cycles.
The sterilisation can be carried out by means of chem-
icals, hot water, or steam. As an example, in the dairy
industry the sterilisation temperature is approximately
145° C (293° F).
It is common practice for pumps to remain stationary
when live steam is present during SIP to ensure no
distortion within seals due to the gaseous state of the
steam and the steam flow distribution. The temper-
ature rise of the seal parts would not be even and
therefore needs to be suitably cooled before pump can
be restarted at low speeds (100 rpm) to remove any
trapped condensate build-up after SIP cycle.
Operation of pump is possible during steam cycles
at low speeds (100 rpm) if there is a quench/barrier/
buffer present within seal housing to provide a lubricat-
ing fluid film.
Please note, a small volume of seal leakage is typical-
ly present on initial start-up as the pump seal faces
rotate to realign back into place. This is temporary
and not a cause of concern as long as pump was not
in operation during any phase where liquid was not
present to lubricate seal face.
If seal leakage remains after an intermediate period of
operation, please contact Alfa Laval for guidance.

287
10
Cleaning
Guidelines

This chapter describes some of the
international standards and guidelines
applicable to Alfa Laval pump ranges.
11.1 Compliance with international
Standards and Guidelines
Alfa Laval pump ranges are available with documented and certified compliance
within a broad spectrum of relevant international and local hygiene standards,
worldwide. This assists the user to significantly reduce the engineering costs of
setting up and operating standard-compliant processing plants around the world.
288
11
Compliance

Compliance
1
1
289
11
Compliance

Please find below some examples of regulations,
standards, and guidelines applicable to our products
used in hygienic applications.
More information can be found in Instruction Manuals
at alfalaval.com.
For special requests please contact your local Alfa
Laval organization.
The mission of 3-A SSI is to enhance product safety
for consumers of food, beverages, and pharmaceuti-
cal products through the development and use of 3-A
Sanitary Standards and 3-A Accepted Practices. The
3-A symbol is a registered mark used to identify equip-
ment that meets 3-A Sanitary Standards for design
and fabrication.
ATEX-directive is the popular name for the European
Directive 2014/34/EU setting the rules for equipment
and protective systems intended for use in potentially
explosive atmospheres.
Compliance to the Regulation (EC) No. 1935/2004.
The framework regulation (EC) No. 1935/2004 regu-
lates food contact materials and articles within EU. It
includes several requirements for materials and articles
intended to come into contact with food to ensure ma-
terial safety. The glass and fork symbol may be used
to indicate that the relevant requirements stated in (EC)
No. 1935/2004 are met.
CE marking is a mandatory conformity mark for
products placed on the market in the European
Economic Area (EEA). With the CE marking on a
product the manufacturer ensures that the prod-
uct conforms with the essential requirements of the
applicable EC directives. The letters “CE” stand for
“Conformité Européenne” (“European Conformity”).
UKCA marking is a mandatory conformity mark
for products placed on the market in Great Britain
(England, Scotland, and Wales). With the UKCA
marking the manufacturer ensures that the product
conforms with the relevant requirements of the
applicable legislations.
Within United States, requirements for food contact
materials and articles are specified by the Food and
Drug Administration (FDA) and are regulated under
the Code of Federal Regulations, Title 21 “Food and
drugs”, Parts 170-199 “Food for human consumption”.
The United States Pharmacopeia (USP) standards,
chapter 87 and 88, and International Organization
for Standardization (ISO) standard 10993, sections 5,
6, 10 and 11, specifies requirements to ensure biocom-
patibility of product contact parts intended to be used
in pharma applications.
The American Society of Mechanical Engineers
Bioprocessing Equipment (ASME BPE) is the
Bioprocess Equipment group of the ASME that
provides engineers and quality control professionals
a measurable way to specify and purchase equipment
for the Biotechnology, Pharmaceutical and Personal
Care Products industries.
Authorized to carry
the 3A symbol
290
11
Compliance

CE
The CE marking is to demonstrate to interested parties
that goods or equipment with this mark comply with
the appropriate directives of the European Community
(Fig. 11a). The appropriate directives are those that
are concerned with the design and manufacture
of goods or equipment. Directives are intended to
facilitate a Single Market in the European Union. With
emerging European standardisation, conflicting nation-
al standards will eventually tend to disappear, as all EU
member states will work to the same standard, with a
few exceptions. Some national differences cannot be
harmonised. In Europe many different languages are
spoken, and some parts are prone to earthquakes,
high winds, heavy snow and extremes of cold and
heat. It is often uneconomic to design equipment
that will withstand all these conditions.
All Alfa Laval pump ranges are CE marked and
conform to the machinery directive 89/392/EEC as
amended by 91/368/EEC, 93/44/EEC and 93/68/
EEC and other relevant directives i.e., ‘Electrical
Equipment Low Voltage Directive 73/23/EEC’ and
‘Electromagnetic Compatibility Directive 89/336/EEC’.
Other applicable standards/specifications which Alfa
Laval pump ranges comply to are as follows:
• EN 292 Parts 1 and 2: 1995 Safety of Machinery
- Basic concepts, general principles for design
• EN 294: 1996 Safety distances to prevent danger
zones being reached by the upper limbs
• EN 60204 Part 1: 2018 Safety of Machinery
- Electrical equipment of machines
- Specification for general requirements
• ISO 9001: 2015 Quality Management System
• ISO 14001: Environmental Management System
3-A
This standard has the purpose of establishing and
documenting the material, fabrication, and installation
(where appropriate) requirements for the engineering
design and technical construction files for all prod-
ucts, assemblies, and sub-assemblies supplied by the
manufacturer (Fig. 11b). The manufacturer has to be
in compliance with the sanitary criteria found in 3-A
Sanitary Standards or 3-A Accepted Practices. The
3-A Sanitary Standards and 3-A Accepted Practices
are applied as suitable sanitary criteria for dairy and
food processing equipment. 3A is subject to 3rd
party
validation according to 3A 02/10 guidelines.
The Alfa Laval pump ranges conform to this 3-A stand-
ard for certain configurations this can be selected and
determined in the AnyTime Configurator.
Authorized to carry
the 3A symbol
Fig. 11a CE Fig. 11b 3-A
291
11
Compliance

FDA
The Food and Drug Administration (FDA) in the US
is the enforcement agency of the United States
Government for food, drug and cosmetics manufactur-
ing. It is responsible for new material approvals, plant
inspections and material recalls (Fig. 11c). In the US,
the ‘Food, Drug and Cosmetic Act’ requires food, drug
and cosmetic manufacturers to prove that their prod-
ucts are safe. The FDA’s primary purpose is to protect
the public by enforcing this Act.
The FDA can:
• Approve plants for manufacturing
• Inspect plants at random
• Write general guidelines for good manufacturing
processes
• Write specific criteria for materials in product
contact
• Have certain expectations regarding design
practices
The FDA cannot:
• Approve equipment outside of a particular use
within a specific system
• Approve materials for use in pharmaceutical
systems
• Write specific engineering or design requirements
for systems
Fig. 11c FDA
292
11
Compliance

USDA
The United States Department of Agriculture (USDA)
is one of three Federal Agencies, along with the
Environmental Protection Agency (EPA) and the U.S.
Food and Drug Administration (FDA), primarily respon-
sible for regulating biotechnology in the United States
(Fig. 11d).
Products are regulated according to their intended
use, with some products being regulated under more
than one agency.
Agricultural biotechnology is a collection of scientific
techniques, including genetic engineering, that are
used to create, improve, or modify plants, animals, and
micro-organisms. Using conventional techniques, such
as selective breeding, scientists have been working
to improve plants and animals for human benefit for
hundreds of years. Modern techniques now enable
scientists to move genes (and therefore desirable traits)
in ways they could not before - and with greater ease
and precision.
The Federal government has a well-coordinated
system to ensure that new agricultural biotechnol-
ogy products are safe for the environment and to
animal and human health. While these agencies act
independently, they have a close working relationship.
• USDA’s Animal and Plant Health Inspection Service
(APHIS) is responsible for protecting American
agriculture against pests and diseases. The agency
regulates the field testing of genetically engineered
plants and certain micro-organisms. APHIS also
approves and licenses veterinary biological sub-
stances, including animal vaccines that may be the
product of biotechnology
• USDA’s Food Safety and Inspection Service (FSIS)
ensures the safety of meat and poultry consumed
as food
• The Department of Health and Human Service’s
Food and Drug Administration (FDA) governs the
safety and labelling of drugs and the nation’s food
and feed supply, excluding meat and poultry
• The Environmental Protection Agency (EPA)
ensures the safety and safe use of pesticidal
and herbicidal substances in the environment
and for certain industrial uses of microbes in the
environment
• The Department of Health and Human Service’s
National Institutes of Health have developed
guidelines for the laboratory use of genetically
engineered organisms. While these guidelines are
generally voluntary, they are mandatory for any
research conducted under Federal grants and they
are widely followed by academic and industrial
scientists around the world
Fig. 11d USDA
293
11
Compliance

USP (United States Pharmacopeia) class VI
USP (United States Pharmacopeia) class VI refers to a
set of standards established by the USP that govern
the biocompatibility and safety of materials used in the
manufacturing of pharmaceutical and medical devices.
Chapter 87 and Chapter 88 of USP class VI specifically
address biological reactivity testing of in vitro and in
vivo materials, respectively.
Chapter 87 focuses on the in vitro biological reactivity
testing of materials used in medical devices. It outlines
various tests and criteria to assess the potential
adverse biological reactions caused by these mate-
rials. The chapter provides guidelines for evaluating
the cytotoxicity (cellular toxicity), sensitization (allergic
reactions), irritation, and other potential harmful effects
of materials when they come into contact with living
tissues.
On the other hand, Chapter 88 addresses the in vivo
biological reactivity testing of materials. It covers the
testing of materials using animal models to assess
their potential adverse effects when implanted or
introduced into living organisms. This includes tests
for acute systemic toxicity, subchronic toxicity, and
implantation effects.
Compliance with USP class VI standards, including
chapters 87 and 88, is crucial for ensuring the safety
and compatibility of materials used in medical devic-
es and pharmaceutical products. Manufacturers and
suppliers are expected to adhere to these standards to
demonstrate that their materials are biocompatible and
pose minimal risks to patients and users. By following
these guidelines, the industry can maintain high stand-
ards of quality and safety in the design and production
of medical devices and pharmaceutical products.
FDA/USP Class VI – ISO 10993
For all Alfa Laval Ultra Pure pumps are the product
wetted Elastomers conforming with FDA USP Class VI.
• All elastomer types conform to USP class VI
chapter 87 and 88
• Extractable testing undertaken to 121° C (250° F)
294
11
Compliance

EN 10204 3.1
With the stringent demands of hygiene within new food
and pharmaceutical plants being built, material trace-
ability of equipment supplied is increasingly important.
The EN 10204 standard defines the different types of
inspection documents required for metallic products.
In particular, 3.1 of this standard refers to inspection
documents being prepared at each stage of manu-
facture and supervised tests performed by the quality
department of the manufacture. The material certifica-
tion has reference all the way back to original steel mill.
EN 10204 2.2
This standard defines documents supplied to the pur-
chaser, in accordance with the order requirements, for
the supply of metallic products such as pumps. This
takes the form of a certificate of conformity and can be
applied to all Alfa Laval pump ranges.
295
11
Compliance

EHEDG
EHEDG stands for European Hygienic Engineering
and Design Group (Fig. 11e). It is a consortium of
equipment manufacturers, food industries, research
institutions, and public health authorities that promotes
hygienic engineering and design principles in the food
and beverage industry.
The primary goal of EHEDG is to provide guidelines
and standards for the design, construction, and
installation of food processing equipment and facilities
to ensure hygienic production processes. By promot-
ing hygienic engineering practices, EHEDG aims to
improve food safety, minimize contamination risks, and
enhance the overall quality of food products.
EHEDG develops and publishes guidelines, recom-
mendations, and best practices for various aspects of
food processing, including equipment design, mate-
rials selection, cleaning and disinfection procedures,
and facility layout. These guidelines are based on
scientific principles and are continuously updated to
incorporate the latest advancements in food safety and
hygiene.
Some key principles emphasized by EHEDG include:
• Cleanability: Equipment should be designed in a
way that allows effective and efficient cleaning.
Smooth surfaces, minimal joints and crevices, and
the use of appropriate materials are crucial for easy
cleaning and prevention of bacterial growth
• Hygienic design: Equipment should be designed
to minimize the risk of product contamination. This
involves considerations such as preventing the
accumulation of product residues, avoiding dead
spaces where bacteria can proliferate, and ensur-
ing proper drainage of liquids
• Material selection: EHEDG provides guidance
on suitable materials for food contact surfaces,
taking into account factors such as resistance to
corrosion, ease of cleaning, and compatibility with
different food products
• Validation and verification: EHEDG emphasizes the
importance of validating and verifying the hygienic
performance of equipment and processes. This
involves conducting tests and assessments to
ensure that the equipment meets the desired hy-
giene standards and that cleaning and disinfection
procedures are effective
Fig. 11e EHEDG
296
11
Compliance

EHEDG and 3A
One significant difference between 3A SSI and EHEDG
lies in their geographical focus. While 3A SSI primarily
caters to the North American market, EHEDG has a
broader international presence and addresses the
needs of European and global industries. This differ-
ence in regional scope leads to variations in regulatory
requirements, manufacturing practices, and market
acceptance.
3-A certification requires only a theoretical review of
design requirements while EHEDG certification reviews
the design both theoretically and practically (using a
standardised hygiene test)
Despite these differences, both 3A SSI and EHEDG
share the common goal of ensuring hygienic equip-
ment design and operation. Manufacturers and
industry professionals consider relevant standards and
guidelines from both organizations, along with other
applicable local regulations, to achieve the highest
level of hygiene and safety in their processes and
products.
The consensus is 3A SSI and EHEDG are collaborating
more and driving the future hygienic design standards
and look to remove national or regional standards as
non-trariff barriers for trade.
ATEX
ATEX stands for “ATmosphères EXplosibles,” which
translates to “Explosive Atmospheres” in English
(Fig. 11f). ATEX is a European Union directive that
outlines the requirements for equipment and protec-
tive systems intended for use in potentially explosive
atmospheres.
For more information on ATEX see section 9.8).
Fig. 11f Ex
297
11
Compliance

Pharma documentation:
Alfa Laval Q-doc is our comprehensive documenta-
tion package for our UltraPure equipment (Fig. 11g).
Based on Good Documentation Practice (GDP), Q-doc
documents every aspect from raw material to delivered
equipment. With full transparency of sourcing, produc-
tion and supply chains it is a simple matter to trace
even the slightest change in material or manufacturing
procedures – even when it comes to spare parts.
Serial No:
This Q Doc contains the following






Date
VAT Registered No: GB 102 5620 64
Registered in England No: 7427524
Registered Office: Birch Road Eastbourne BN23 6PQ
Equipment Documentation
SX UltraPure
Page 5 of 5
QC Inspector 19 Jul 2023
Responsibilities
The responsible person from each department who have performed test or entered data to this document must
approve and sign. By signing this document the responsible person hereby declares that the instructions are
followed and the requirements met in the appropriate procedures or Technical Specification of this document.
Pump Test Certificate
Surface Finish Certificate
Hydrostatic Pressure Test Certificate
Delta Ferrite Conformance
Supplier Heat Certificates
# Classified by Alfa Laval as: Business
SX UltraPure
Product wetted non metallic parts
Qty Material
Lot Number
Cure Date
Batch No
Compound ID
2 EPDM USP VI
230307005
24 Nov 2022
88338
R43
2 EPDM USP VI
230307010
20 Jul 2022
86720B
R43
1 EPDM USP VI
220208010
13 Jan 2022
2201130008
E70Q
2 EPDM USP VI
220718001
28 Jun 2022
2206280056
E70Q
2 EPDM USP VI
211110005
17 Oct 2021
2110170065
E70Q
2 EPDM USP VI
220203012
05 Jan 2022
106540
2107
2 EPDM USP VI
211215026
01 Jan 2021
083802
2107
2 CARBON
220222009 384269
R60
2 Silicon carbide
230329006 400261
R36
2 Silicon carbide
220310003 384036
R36
9630069798
R5610.124
ROTARY RING R00 SC SX4
9630069823
R5630.134
STATIC SEAT R00 SC/SC 3.1 SX4
9630929689
1556.330
O RING EPDM USP VI
9630069835
R5610.134
ROTARY RING R00 C DBL OUT SX4
9630854854
1556.027
O RING EPDM USP VI
9630071265
1555.830
O RING EPDM USP VI
9630862195
1556.144
O RING EPDM USP VI
9630069421
5382.305
CUP SEAL EPDM USP VI SX3-4
9630069426
5382.405
CUP SEAL EPDM USP VI SX4-5
9630070401
5381.405
JOINT RING EPDM USP VI SX4
Page 4 of 5
Serial No:
AL Article No
Item No
Item Description
SX UltraPure
Product wetted metallic parts, 3.1 according to EN 10204 (MTR) traceability
Qty Material Lot Number Heat No
1 1.4404/316L 280682 567383
2 1.4462 220222009 433620
2 1.4404/316L 282383 565670
2 1.4404/316L 230220002 174040
1 1.4404/316L 279839 59391
2 1.4404/316L 220730001 1MDJ
2 1.4460/1.4462 220310003 277396
2 1.4404/316L 230515006 YX22072108
9630069823
R5630.134
STATIC SEAT R00 SC/SC 3.1 SX4
9630103857
5002.650.A
WOC TRICLAMP 65mm 3.1
ROTOR RETAINER 3.1 SX4/063
9630110664
5804.010.A
ROTORCASE 3.1 SX4/063
9630074472
5670.174
SEAL DRIVE INSERT 3.1 SX4
Please note that the table above is a Lot Tracing Report showing the components issued to the Shop Orders. It is not a Bill of Materials and should not be used to
order spares. For Spares enquiries please contact Eastbourne Customer Support.
AL Article No
Item No
Serial No:
Page 3 of 5
Item Description
9630070403
5130.434
COVER ROTORCASE 3.1 SX4
9630069835
R5610.134
ROTARY RING R00 C DBL OUT SX4
9630110663
5780.063K.A
ROTOR 4L SS 10 BAR 3.1 SX4/063
9630070339
5900.214
SX UltraPure
Declaration of Compliance
Alfa Laval Eastbourne Ltd
Birch Road, Eastbourne, BN23 6PQ, UK
Phone: +44 (0) 1323 412555
E-mail: info@alfalaval.com
Compliance with Regulation (EC) No: 1935/2004
Compliance to EN 10204 type 3.1 (MTR) *
Compliance to the U.S. Food Drug Administration CFR 21 §177.2600
Compliance to the U.S. Food Drug Administration (considering mechanical seal faces)
Compliance to the United States Pharmacopeia (USP)
TSE (Transmissible Spongiform Encephalopathy) Declaration
Surface Finish Declaration
* 3.1 certificates (MTR’s) are attached to this document
Lars Kruse Andersen, Global Product Quality Manager, Alfa Laval
In accordance with Alfa Laval quality procedures we declare that in the above equipment the surface finish of the
product wetted metallic parts complies with the requirements of the order and unless requested otherwise is no
greater than 0.8 Microns Ra.
Where an improved surface finish or electro polishing has been specified we declare the surface finish of the
product wetted metallic parts complies with the requirements of the order as recorded in the attached certificate.
We declare that the above mentioned equipment complies with Regulation (EC) No. 1935/2004 regarding
“Materials and articles intended to come into contact with food”.
We declare that in the above equipment the product wetted steel parts comply with the requirements of the order as
specified in our EN 10204:2004 Inspection certificate type 3.1.
We declare that the product wetted elastomers are in compliance with the U.S. Code of Federal Regulations (CFR)
section 21 Food and Drug Administration (FDA), Part 177 (Indirect Food Additives: Polymers), Section 2600
(Rubber Articles Intended for Repeated Use). FDA Declarations from our suppliers can be forwarded upon request.
We hereby certify that on pumps of our manufacture, the materials from which the mechanical seal faces are
produced are accepted by the U.S. Food and Drug Administration’s regulations (FDA) to be used within food
li ti
If specified as USP Class VI the product wetted elastomer compounds have been tested and certified by an
independent laboratory to be in compliance with the criteria of the U.S. Pharmacopeia 88, Class VI extraction tests.
R36 Silicon carbide seal face material has been tested and certified by an independent laboratory to meet the
requirements of the U.S. Pharmacopeia Chapter 87.
We declare that the above equipment has never been in contact with any compound derived from animal sources.
Consequently this equipment does not contain Specific Risk Materials (SRM`s) associated with risk of TSE. TSE
Declarations from our suppliers can be forwarded upon request.
Page 2 of 5
Serial No:
Fig. 11g Example of standard Q-Doc for SX UltraPure
Alfa Laval SX UltraPure
Rev. 3.4
PID reference:
Equipment documentation
Page 1 of 5
Order information
Item Description:
Serial No.:
Doc. ID No.: Alfa Laval Q Doc SX UltraPure
SX UP4/063 PUMP 65mm TRICLAMP
Item No.:
Order No.:
DOWNLOAD THIS Q-DOC AT
www.alfalaval.com/certificates
298
11
Compliance

299

This chapter covers guidelines relating
to pump installation, system design and
pipework layout.
12.1 General
To ensure optimum pump operation it is important
that any pump unit to be used is installed to the best
engineering practice.
300
12
Installation
Guide

Installation Guide
12
301
12
Installation
Guide

12.1.1 System Design
When designing a pumping system, the following
points should be taken into consideration:
• Confirm the Net Positive Suction Head (NPSH)
available from the system exceeds the NPSH
required by the pump, as this is crucial for ensuring
the smooth operation of the pump and preventing
cavitation
• Take care with designing suction lifts and manifold/
common suction lines for two positive displace-
ment pumps running in parallel, as this may cause
vibration or cavitation (see Fig. 12.1.1a). It is impor-
tant to note that each pump have their own
NPSH required value so NPSH available on a
shared suction line requires sufficient availability
on both pumps. Recommendation is to take both
NPSHr values for a total and add an additional
1 m lc margin to NPSHa for suitable operation
• Protect the pump against blockage from hard solid
objects e.g., nuts, bolts etc. Also protect the pump
from accidental operation against a closed valve by
using relief valves, pressure switches and current
limiting/tripping devices
• Fit suction and discharge pressure monitor points
for diagnostic purposes
• Fit valves, if two pumps are to be used on mani-
fold/common discharge lines
• Make the necessary piping arrangements as per
individual requirements of the pump specification
as detailed in the operating manual for flushing
• Allow at least 1 m for pump access/maintenance
all around the unit
• Do not subject pumps to rapid temperature chang-
es, as pump seizure can result from thermal shock
Fig. 12.1.1a Avoid common suction lines
Discharge line
Suction line
Plan view
12
Installation
Guide

12.1.2 Pipework
Both the suction and discharge piping should be
aligned and independently supported so that the pipe-
work does not create any undesired strain against the
connections of the pump. Pipe strain is a leading factor
in causing shaft misalignment.
Pipework support should be balanced and secured
so that when fluid is introduced, there is no movement
that would cause pipe strain on the pump.
The maximum allowable forces and moments for an
Alfa Laval pump can be found in the operating manual.
For optimal pipework design, provision needs to be
made to the pipework to ensure unwanted effects
such as hydraulic noise, vibration and cavitation are
minimised.
The following should be taken into consideration
• Have short, wide inlet pipework to reduce friction
losses in the pipework thereby improving the NPSH
available
• Avoid bends, tees, and any restrictions close to
either suction or discharge side of pump. Use long
radius bends wherever possible
• Alfa Laval recommends x10 the pipe diameter of
straight pipework before and after the pump to
allow for steady flow conditions that reduce turbu-
lence and unwanted vibration
• Provide isolating valves on each side of the pump
when necessary
• Keep pipework horizontal where applicable to
reduce air locks. Include eccentric reducers on
suction lines and a positive gradient slope feeding
to pump inlet being ideal
12.1.3 Weight
The weight of the pump and drive unit should be con-
sidered for lifting gear requirements.
Consult the pumping unit’s operating manual on best
methods for handling.
12.1.4 Electrical Supply
Ensure that there is an adequate electrical supply to
the pump drive unit. This supply should be compatible
with the electric motor selected and managed by a
qualified electrician for installation purposes.
303
12
Installation
Guide

12.2 Flow Direction
12.2.1 Centrifugal Pumps
A centrifugal pump should never be operated in the
wrong direction of rotation with fluid within the pump
(Fig. 12.2.1a). It is possible to check this in two ways
as follows:
1. Pump with impeller screw fitted
• Start and stop the motor momentarily (without fluid
in the pump)
• Ensure that the direction of rotation of the motor
fan is clockwise as viewed from the rear end of
the motor (Fig. 12.2.1b)
2. Pump without impeller screw fitted
• With this method the impeller should always be
removed before checking the direction of rotation
(Fig. 12.2.1c)
• The pump should never be started if the impeller
is fitted, and the pump casing has been removed
• If dealing with a LKH Prime with an airscrew,
always remember to remove the air screw and
impeller before checking the direction of rotation
• Start and stop the motor momentarily
• Ensure that the direction of rotation of the stub
shaft is anti-clockwise as viewed from the pump
inlet (Fig. 12.2.1d)
Outlet
Inlet
Fig. 12.2.1b Pump with impeller screw fitted
Fig. 12.2.1d Pump without impeller
Stub shaft
Fig. 12.2.1a Correct direction of flow
Fig. 12.2.1c Pump without impeller screw fitted
304
12
Installation
Guide

12.2.2 Rotary Lobe Circumferential Piston Pumps
The direction of flow is dictated by the direction of
drive shaft rotation. Reversing the direction of rotation
will reverse the flow direction (Fig. 12.2.2a).
Both Rotary Lobe and Circumferential Piston pumps
are capable of full bi-directional flow without configura‑
tion modification.
Fig. 12.2.2a Flow direction
Outlet Outlet
Inlet
Outlet
Inlet
Inlet
Outlet
B B
A A
B
A B
A
A: Suction
B: Discharge
A: Suction
B: Discharge
305
12
Installation
Guide

12.2.3 Twin Screw Pumps
The direction of flow is dictated by the direction of
drive shaft rotation. Reversing the direction of rotation
will reverse the flow direction. It is important to note,
the twin screw pump will have been built for a specific
flow direction at time of order. This is highlighted by
the arrow on the pump casing and the drive shaft as
indication of which direction flow will occur via correct
rotation (Fig. 12.2.3a).
Note:
The Alfa Laval Twin Screw pump may be operated in
reverse to that originally intended but differential pres-
sure limitations in accordance to pump configuration
must be considered – Refer to instruction manual for
further details.
1)
2)
Fig: 12.2.3a 1) Standard flow direction - Front: Inlet/Top: Outlet 2) Reversed flow direction – Top: Inlet/Front: Outlet
306
12
Installation
Guide

12.3 Baseplate Foundations
Positive Displacement Pumps
Success to pump longevity begins with a solid foun-
dation. In general, a pump should be mounted on a
strong baseplate and supported by a strong concrete
foundation to absorb any vibration, strain or shock and
form a permanent rigid support for the baseplate and
pumping unit.
Positive displacement pumps when supplied with a
drive unit are normally mounted on a baseplate. Alfa
Laval standard baseplates have pre-drilled fixing holes
to accept base retaining bolts (Fig. 12.3b).
Methods of anchoring the baseplate to the foundation
are varied, they can be studs embedded in the con-
crete either at the pouring stage as shown below, or
by use of epoxy type grouts. Alternatively mechanical
fixings can be used.
Optimal foundations should be approximately 150 mm
longer and wider than the provided baseplate. In ad-
dition, the depth of the foundation should be propor-
tional to the size of the complete pump unit with typical
standard value being at a depth of x10 the foundation
bolt diameter.
The drawing (Fig. 12.3b) above shows two typical
methods for foundation bolt retaining. The sleeve
allows for ‘slight’ lateral movement of the bolts after
the foundation is poured. Rag or wastepaper can be
used to prevent the concrete from entering the sleeve
while the foundation is poured. A minimum of 14 days
is normally required to allow the curing of the concrete
prior to pump unit installation.
Fig. 12.3b Baseplate fixing
Baseplate fixing holes
A
A = Sleeve
B = Lug welded to bolt head
C = Waste put around bolt
before pouring concrete
C
B
3D
D
Dmin
0.5D
min
A
4D
10D
A = Foundation surface
left rough to anchor grout
Fig. 12.3c Foundations
307
12
Installation
Guide

Ball Foot Baseplate with Adjustable Feet
The pumping unit can be supplied with an optional ball
foot baseplate with height adjustable feet (Fig. 12.3d).
When used:
• Ensure the floor is level and can support the weight
of the complete unit
• Ensure the unit is supported by all feet equally
Note:
These two points on suitable foundation are also appli-
cable to centrifugal pumps when installed.
The 3A standard on positive displacement pumps
requires a minimum clearance between the lowest part
of the base, pump, motor, or drive and for the floor to
be no less than 100 mm (4 in).
Fig. 12.3d Ball Foot baseplate
308
12
Installation
Guide

12.4 Coupling Alignment
(Positive Displacement Pumps)
Before the pump unit is installed it is important to
ensure that the mounting surface is flat to avoid
distortion of the baseplate. This will cause pump/motor
shaft misalignment and pump/motor unit damage
(Fig. 12.4a).
Once the baseplate has been secured, the pump shaft
to motor shaft coupling alignment should be checked
and adjusted where necessary as it is possible for
assembled units to shift out of tolerance during transit.
Coupling alignment is achieved by checking the maxi-
mum angular and parallel allowable misalignments for
the couplings as stated by the coupling manufacturers
that can be located within operating manuals.
Misalignment can lead to premature seal and bearing
failure with increased noise output. Misalignment is
often caused by the following:
• Improper mounting/shimming of the equipment
when fitting/installing
• Pipe strain caused by improper alignment to the
pump’s fluid connections
• Pipe strain caused by improper support of the pipe
Fig. 12.4a Parallel and angular misalignment
Parallel misalignment
Angular misalignment
309
12
Installation
Guide

Always use two drain valves
If the LKH Prime Pump is fitted with the drain option;
never short circuit the drain connections as this will
reduce the air release capacity (Fig. 12.5a).
12.5 Considerations for LKH Prime Centrifugal Pump
To ensure optimal function of the self-priming capac-
ity, LKH Prime must be installed in such a way that it
ensures liquid is in the pump on start-up e.g., with a
swan neck design as illustrated (Fig. 12.5b).
Note:
Max running time when releasing air should not
exceed 15 min.

Fig. 12.5a Incorrect use Fig. 12.5b Correct use
12
Installation
Guide

Installation guidelines
1. Suction considerations
• Ensure the suction line is designed so the pump is
liquid filled at start up, e.g. swan neck (Fig. 12.5c)
• Design suction line with slope down toward the
pump to avoid air entrapments
• Ensure NPSHa NPSHr under all duty conditions
including all temperatures
• Controlled start/stop of pump e.g. Level Switch
(LS)
• Do not start the LKH Prime before tank bottom is
liquid filled
• Stop the LKH Prime during phase changes
S
min D
min
LKH Prime 10
LKH Prime 20
200 mm 1.5 m
2 pipe
LKH Prime 40 200 mm 1.5 m
3 pipe or
2 m
2 pipe
Table 12.5.a
2. General considerations
• Minimum speed for effective air evacuation is 2800
RPM
• Air evacuation ability improves with higher speed
(Maximum speed 3600 RPM)
• The LKH Prime must be sized for the specific duty
point
3. Discharge considerations
• Place check valve as far away from the pump as
possible
• Replace check valve with automated valve, if
possible
Note:
The LKH Prime is NOT a one-to-one replacement of
the MR liquid-ring pump.
S
D
Fig. 12.5c Recommended start-up outlay
4
3
2
5
LS
1
Fig 12.5d Installation example
1. Suction line
2. LKH Prime Pump
3. Discharge line
4. Check valve
5. Level switch
311
12
Installation
Guide

12.6 Pre-start Checklist
• Check the pipework system has been purged to
remove debris
• Check all obstructions have been removed from
pipework and pump
• Check pump connections and pipework joints are
tight
• Check lubrication levels are correct
• Check seal flushing is connected if applicable
• Check all safety guards are in place
• Check that inlet and outlet valves are open
Note:
Where available, commissioning plugs should be used
to reduce risk of any component damage because of
debris becoming trapped between rotating element
and casing.
12.6.1 Fastenings
If pump is to be disassembled for any reason it is
imperative that upon assembly all fastenings are tight-
ened to the recommended torque values as shown in
the instruction manual.
12
Installation
Guide

This chapter offers possible causes and
solutions to most common problems
found in pump installation and operation.
13.1 General
Pumps are critical components in many industrial
processes and applications. They are used to transfer
fluids, gases, or other substances from one location to
another. Problems with pumping equipment cause not
only inconvenience, but also contribute to loss of pro-
duction. An efficient operation depends on trouble-free
pumping. Effective troubleshooting of pumps is crucial
for minimising downtime and preventing further dam-
age to equipment, ultimately saving time and money.
Pumps are likely to be the most vulnerable compo-
nents and when trouble can arise, the symptoms
frequently show the pump to be at fault regardless of
what may be wrong. The problem is usually caused
by inadequate control of the pumped fluid or a change
in operating requirements of which the system or
pump is not capable of handling or a component
malfunction.
314
13
Troubleshooting

Troubleshooting
13
315
13
Troubleshooting

The most common problems found are generally as
follows and explained in section 13.2:
• Loss of flow
• Loss of suction
• Low discharge pressure
• Excessive noise or vibration
• Excessive power usage
• Rapid pump wear
• Seal leakage
Before starting to correctly identify the problem it is
important to gather as much information relating to the
process as follows:
• Reconfirm original duty conditions pump was sized
towards
• What has changed in the process since operation
was last satisfactory i.e., pressure, temperature,
fluid viscosity etc.
• Was the system undergoing routine maintenance
• Were any new or repaired components omitted to
be fitted
• When was the pump last serviced
• What was the appearance and condition of the
pump internal components
• How long did the pump operate before the
problem
• Any changes in pump noise or vibration
Diagnosis of problems will be greatly
assisted by having pressure gauges
fitted to both pump inlet and outlet.
316
13
Troubleshooting

13.2 Common Problems
13.2.1 Loss of Flow
A simple cause of this could be incorrect direction of
shaft rotation on a centrifugal pump, which although
obvious is often overlooked.
Loss of flow can be caused by excessive discharge
pressure and/or by a change in fluid viscosity.
In general terms:
• For a positive displacement pump, if the viscosity is
significantly reduced, the pump’s rated flow will be
reduced, more so for higher pressure operation
• For a centrifugal pump if the viscosity is increased,
the pump’s rated flow will be decreased
13.2.2 Loss of Suction
Loss of suction can be minor, causing little, short-term
damage or sufficiently major to catastrophic damage.
Loss of suction means fluid is not reaching the pump-
ing elements or not reaching them at a sufficiently
high pressure to keep the fluid being pumped in a fluid
state. Loss of suction can be interpreted as the inability
to prime, cavitation or a gas content problem.
Positive displacement pumps can be classed as
‘self-priming’. This means that within limits, unique
to each technology, they are capable of evacuating
(pumping) a modest amount of air from the suction
side of the pump to the discharge side of the pump.
Filling the inlet system with fluid or at least filling the
pump (wetted pumping elements) will make a consid-
erable improvement in the pump’s priming capability.
The LKH Prime centrifugal pump range is specially
designed to be self-priming with its air screw design.
Cavitation is caused by insufficient system inlet
pressure to the pump. This can be caused by an inlet
system restriction, excessive fluid viscosity or exces-
sive pump speed. Inlet restrictions can include dirty or
clogged inlet strainers, debris floating in the fluid
supply that covers the inlet piping intake, or rags.
If the fluid is cooler than design temperature, its
viscosity may be too high causing excessive friction
(pressure loss) in the inlet piping system. Cavitation
is frequently accompanied by noise, vibration and
significant increase in discharge pressure pulsation.
If a pump is allowed to cavitate over long periods this
will cause damage to the pump head components.
The surface of these components are typically
perforated and pitted.
Gas in the inlet pipework has the same impact on
pump operation and creates the same symptoms as
cavitation. This can occur under other circumstances
such as a pump operating at an inlet pressure below
local atmospheric pressure. In this instance it is quite
likely that air is being drawn into the pipework through
a loose pipe connection or pump casing joint, leak-
ing inlet valve stem, defective or otherwise damaged
joint gasket in the pipework system. In recirculating
systems, such as a lubrication system where the fluid
pumped is continuously returned to a supply source
or tank, if the tank and return lines are not adequately
designed, located and sized, air is easily entrained in
the oil and immediately picked up by the pump inlet
system. Be sure fluid level at its source is at or above
minimum operating levels. Lines returning flow to a
supply tank should terminate below minimum fluid
level.
317
13
Troubleshooting

13.2.3 Low Discharge Pressure
Low discharge pressure can only be caused by
loss of flow. Pump discharge pressure is caused
only by the system’s resistance to the flow provided
by the pump. Either the pump is not providing the
flow expected or the system is not offering the expect-
ed resistance to that flow and would not be a result
of incorrect pump selection but rather system/process
design. It is possible that flow is being restricted into
the pump (cavitation), usually accompanied by noise
and vibration, the pump is not producing its rated
flow (pump worn or damaged), or the pump flow is
bypassing rather than being delivered into the system
as intended.
13.2.4 Excessive Noise or Vibration
Excessive noise and/or vibration can be a symptom
of cavitation, mechanical damage to pump assem-
bly, misalignment of drive or harmonics with other
elements of the system. Cavitation is especially true
if the discharge pressure is fluctuating or pulsating.
Mechanical causes of noise and vibration include shaft
misalignment, loose couplings, loose pump and/or
driver mountings, loose pump and/or driver guards,
worn or damaged driver or pump bearings or valve
noise that seems to be coming from the pump. Valves,
especially on the discharge side of the pump can
sometimes go into a hydraulic vibration mode caused
by operating pressure, flow rate and the valve design.
Resetting or a change in an internal valve component
is usually sufficient to solve the problem.
13.2.5 Excessive Power
Excessive power consumption can be caused by
either mechanical or hydraulic problems. Mechanical
causes include imminent bearing failure, pumping
elements rubbing which can lead to a pump seizure
and poor shaft alignments. Too high viscosity can
result in the motor overloading.
• For a positive displacement pump, too high dis-
charge pressure can cause the motor to overload
• For a centrifugal pump, too high capacity (too
low discharge pressure) can cause the motor to
overload
13.2.6 Rapid Pump Wear
Rapid wear of pump head components is either
caused by abrasives being present in the fluid, chem-
ical corrosion, loss of shaft support (bearing failure),
or operation at a condition for which the pump is not
suitable i.e., cavitation, excessively high pressure
or high temperature. To avoid any abrasive foreign
material entering the pump, strainers or filters should
be employed wherever possible and practical. Rapid
wear is sometimes not wear in the sense of a non-du-
rable pump, but really a catastrophic pump failure that
occurred very quickly. Looking at the pump’s internal
parts alone may not provide much help in identifying
the cause, thus the importance of knowing what was
occurring in the time period immediately preceding
detection of the problem.
318
13
Troubleshooting

13.2.7 Seal Leakage
Mechanical seals fitted to pumps can be seen as the
weakest point. Special care should be taken to ensure
the correct seal configuration for the application is
installed i.e., mounting attitude, seal face combination
and elastomer selection.
Apart from mis-selection and poor servicing, seal leak-
age can be due to pump cavitation, too high discharge
pressure, pumps being allowed to run dry without suit-
able liquid present for seal operation and unexpected
solids in the fluid.
319
13
Troubleshooting

13.3 Problem Solving Table
The table shown offers probable causes and solutions
to the most common problems encountered.
In the parenthesis ( ) next to the particular solution
given you will find annotation relating to what pump
type the solution is for.
i.e.,
• ce = Centrifugal Pump
• pd = Positive Displacement Pump
See table 13.3a on the following pages.
For further in-depth analysis into troubleshooting
guidance on a particular pump technology with-
in Alfa Laval’s portfolio, please see documents
“Troubleshooting PD Pumps” and “Troubleshooting
Centrifugal Pumps”.
320
13
Troubleshooting

Problem Probable Causes Solutions
No
flow
Under
capacity
Irregular
discharge
Low
discharge
pressure
Pump
will
not
prime
Prime
lost
after
starting
Pump
stalls
when
starting
Pump
overheats
Motor
overheats
Excessive
power
absorbed
Noise
and
vibration
Pump
element
wear
Syphoning
Seizure
Mechanical
seal
leakage
  Incorrect direction of rotation Reverse motor (ce, pd)
 Pump not primed Expel gas from suction line and pumping chamber
and introduce fluid (ce, pd)
     Insufficient NPSH available Increase suction line diameter (ce, pd)
Increase suction head (ce, pd)
Simplify suction line configuration and reduce length
(ce, pd)
Reduce pump speed (pd)
Decrease fluid temperature (ce)
- check effect of increased viscosity
    Fluid vaporising in suction line Increase suction line diameter (ce, pd)
Increase suction head (ce, pd)
Simplify suction line configuration and reduce length
(ce, pd)
Reduce pump speed (pd)
Decrease fluid temperature (ce)
- check effect of increased viscosity
    Air entering suction line Remake pipework joints (ce, pd)
   Strainer or filter blocked Service fittings (ce, pd)
     Fluid viscosity above rated
figure
Increase fluid temperature (ce, pd)
Decrease pump speed (pd)
Increase motor speed (ce)
Check seal face viscosity limitations (ce, pd)
  Fluid viscosity below rated figure Decrease fluid temperature (ce, liq, rlp)
Increase pump speed (pd)
     Fluid temperature above rated
figure
Cool the pump casing (ce, pd)
Reduce fluid temperature (ce, pd)
Check seal face and elastomer temperature
limitations (ce, pd)
   Fluid temperature below rated
figure
Heat the pump casing (ce, pd)
Increase fluid temperature (ce, pd)
   Unexpected solids in fluid Clean the system (ce, pd)
Fit strainer to suction line (ce, pd)
If solids cannot be eliminated, consider fitting dou-
ble mechanical seals (ce, pd)
       Discharge pressure above rated
figure
Check for obstructions i.e. closed valve (ce, pd)
Service system and change to prevent problem
recurring (ce, pd)
Simplify discharge line to decrease pressure (ce, pd)
Table 13.3a - continues on the next page
321

Problem Probable Causes Solutions
No
flow
Under
capacity
Irregular
discharge
Low
discharge
pressure
Pump
will
not
prime
Prime
lost
after
starting
Pump
stalls
when
starting
Pump
overheats
Motor
overheats
Excessive
power
absorbed
Noise
and
vibration
Pump
element
wear
Syphoning
Seizure
Mechanical
seal
leakage
Packed
gland
leakage
Seal flushing inadequate Increase flush flow rate (ce, pd)
Check that flush fluid flows freely into seal
area (ce, pd)
   Pump speed above rated figure Decrease pump speed (pd)
 Pump speed below rated figure Increase pump speed (pd)
     Pump casing strained by pipework Check alignment of pipes (ce, pd)
Fit flexible pipes or expansion fittings (ce, pd)
Support pipework (ce, pd)
    Flexible coupling misaligned Check alignment and adjust mountings
accordingly (pd)
    Insecure pump driver mountings Fit lock washers to slack fasteners and
re-tighten (pd)
     Shaft bearing wear or failure Refer to pump maker for advice and replace-
ment parts (pd)
    Insufficient gear case lubrication Refer to pump maker’s instructions (pd)
     Metal to metal contact of pumping
element
Check rated and duty pressures (ce, pd)
Refer to pump maker (ce, pd)
  Worn pumping element Fit new components (ce, pd)
  Rotor case cover relief valve
leakage
Check pressure setting and re-adjust if
necessary (SRU only)
Examine and clean seating surfaces (SRU
only)
Replace worn parts (SRU only)
  Rotor case cover relief valve
chatter
Check for wear on sealing surfaces, guides
etc - replace as necessary (SRU only)
 Rotor case cover relief valve incor-
rectly set
Re-adjust spring compression - valve should
lift approx. 10% above duty pressure (SRU
only)
  Suction lift too high Lower pump or raise fluid level (ce, pd)
 Fluid pumped not compatible with
materials used
Use optional materials (pd)
 No barrier in system to prevent
flow passing back through pump
Ensure discharge pipework higher than
suction tank (pd)
 Pump allowed to run dry Ensure system operation prevents this (ce,
pd)
Fit single or double flushed mechanical seals
(ce, pd)
 Faulty motor Check and replace motor bearings (ce, pd)
 Too large clearance between
impeller and back plate/casing
Reduce clearance between impeller and
back plate casing (ce)
 Too small impeller diameter Fit larger size impeller - check motor size (ce)
 Pumping element missing e.g.
after service
Fit pumping element (ce, pd)
Table 13.3a - continued

323
13
Troubleshooting

This chapter includes a summary of
nomenclature and formulas used in
this handbook. Various conversion
tables and curves are also shown.
324
14
Technical
Data

Technical Data
14
325
14
Technical
Data

14.1 Nomenclature
Symbol Description Symbol Description
A Area QL Fluid Losses through Impeller
Casing Clearances
D Tube Diameter q Pump Displacement
F Force r Radius
fD Darcy Friction Factor Ra Surface Roughness
g Gravity Re Reynolds Number
H Total Head SG Specific Gravity
Hs Total Suction Head T Shaft Torque
Ht Total Discharge Head V Fluid Velocity
hfs Pressure Drop in ALiCE γ (greek letter ‘gamma’) Specific Weight
hft Pressure Drop in Discharge Line δ (greek letter ‘delta’) Total
hs Static Suction Head ε (greek letter ‘epsilon’) Relative Roughness
ht Static Discharge Head η (greek letter ‘eta’) Total Efficiency
L Tube Length ηh Hydraulic Efficiency
n Pump Speed ηm Mechanical Efficiency
Pa Pressure Absolute above
Fluid Level
ηoa Overall Efficiency
Pf Pressure Loss due to Friction ηv Volumetric Efficiency
Ps Vacuum or Pressure in a Tank on
Suction Side
μ (greek letter ‘mu’) Absolute Viscosity
Pt Pressure in a Tank on Discharge
Side
ν (greek letter ‘nu’) Kinematic Viscosity
Pv Power/Viscosity Factor ρ (greek letter ‘rho’) Fluid Density
Pvp Vapour Pressure ω (greek letter ‘omega’) Shaft Angular Velocity
Q Capacity
Table 14.1a
14
Technical
Data

14.2 Formulas
Designation Formula Comments
Where
to find
Product
Viscosity ν = μ
ρ
Where:
ν = Kinematic Viscosity (mm2
/s)
μ = Absolute Viscosity (mPa.s)
)
2.1.2
or
ν = μ
SG
Where:
μ = Absolute Viscosity (cP)
or
μ = ν x SG 1 Poise = 100 cP
1 Stoke = 100 cSt
Flow
Velocity V = Q
A
Where:
Q = Capacity (m3
/s)
A = Tube Area (m2
)
2.1.7
or
V = Q x 353.6
D2
Where:
Q = Capacity (m3
/h)
or
V = Q x 0.409
D2
Where:
or
V = Q x 0.489
D2
Where:
Table 14.2a - continues next page
327
14
Technical
Data

Where
to find
Reynolds Number
(ratio of inertia forces
to viscous forces)
Re = D x V x ρ
µ
Where:
ρ = Density (kg/m3
)
µ = Absolute Viscosity (Pa.s)
2.1.7
or
Re = D x V x ρ
µ
Where:
ρ = Density (kg/m3
)
or
Re = 21230 x Q
D x µ
Where:
or
Re = 3162 x Q
D x ν
Where:
or
Re = 3800 x Q
D x ν
Where:
Pressure/Head
Pressure
(total force per unit
area exerted by a fluid)
P = F
A
Where:
F = Force
A = Area
2.2.2
Static Pressure/Head
(relationship between
pressure and elevation)
P = ρ x g x h Where:
)
)
2.2.2
or
P = h x SG
10
Where:
P = Pressure/Head (bar)
or
P = h x SG
2.31
Where:
P = Pressure/Head (PSI)
h = Height of Fluid (ft)
Total Head H = Ht – (± Hs) Where:
Ht = Total Discharge Head
Hs = Total Suction Head
2.2.2
328
14
Technical
Data

Where
to find
ht = Static Discharge Head
hft = Pressure Drop in Discharge Line
pt 0 for Pressure
pt 0 for Vacuum
pt = 0 for Open Tank
2.2.2
Total Suction Head Hs = hs - hfs + (± ps) Where:
hs = Static Suction Head
0 for Flooded Suction
0 for Suction Lift
hfs = Pressure Drop in Suction Line
ps 0 for Pressure
ps 0 for Vacuum
ps = 0 for Open Tank
2.2.2
Friction Loss
(Miller equation)
Pf = fD x L x ρ x V2
D x 2
Where:
Pf = Friction Loss (Pa)
fD = Friction Factor (Darcy)
L = Tube Length (m)
)
2.2.2
or
Pf = 5 x SG x fD x L x V²
D
Where:
Pf = Friction Loss (bar)
L = Tube Length (m)
or
Pf = 0.0823 x SG x fD x L x V²
D
Where:
Pf = Friction Loss (PSI)
Darcy Friction Factor fD = 64
Re
Where:
Re = Reynolds Number
2.2.2
329
14
Technical
Data

Where
to find
NPSHa
(Net Positive Suction
Head available)
NPSHa = Pa ± hs – hfs – Pvp
(+hs for flooded suction)
(– hs for suction lift)
Where:
(bar)
hs = Static Suction Head (m)
hfs = Pressure Drop in Suction Line (m)
Pvp = Vapour Pressure (bar a)
2.2.4
or
Where:
(PSI)
hs = Static Suction Head (ft)
hfs = Pressure Drop in Suction Line (ft)
Pvp = Vapour Pressure (PSIA)
Power
Hydraulic Power
(theoretical energy
required)
Power (W) = Q x H x ρ x g Where:
Q = Capacity (m3
/s)
H = Total Head (m)
)
)
7.2.1
or
Power (kW) = Q x H
k
Where:
H = Total Head (bar)
k = 600
or
Power (hp) = Q x H
k
Where:
H = Total Head (PSI)
k = 1715
or
Power (hp) = Q x H
k
Where:
H = Total Head (PSI)
k = 1428
Required Power
(power needed at the
pump shaft)
Hydraulic Power
Efficiency (100% = 1.0)
7.2.2
Torque
Torque Torque (Nm) =
Required Power (kW) x 9550
Pump Speed (rev/min)
7.2.3
or
Torque (kgf m) =
Required Power (kW) x 974
or
Torque (ft lb) =
Required Power (hp) x 5250
330
14
Technical
Data

Where
to find
Efficiency
Hydraulic Efficiency
(ηh)
Pump Head Loss (m) x 100%
Total Head (m)3
7.2.4
Mechanical Efficiency
(ηm)
1 - Pump Mech. Losses x 100%
Required Power
7.2.4
Volumetric Efficiency
(Centrifugal and Liquid
Ring Pumps)
ηv = Q x 100%
Q + QL
Where:
ηv = Volumetric Efficiency
Q = Pump Capacity
QL = Fluid Losses due to Leakage through
the Impeller Casing Clearances
7.2.4
Volumetric efficiency
(Rotary Lobe Pumps)
ηv = Q x 100%
q
Where:
ηv = Volumetric Efficiency
Q = Pump Capacity
q = Pump Displacement
7.2.4
Pump Efficiency (ηp) Water Horse Power x 100%
Required Power
or
ηp = Q x H x ρ x g
w x T
Where:
ηp = Pump Efficiency
Q = Capacity (m3/s)
)
)
w = Shaft Angular Velocity (rad/s)
T = Shaft Torque (Nm)
7.2.4
Overall Efficiency (ηoa) Water Horse Power x 100%
Drive Power
7.2.4
Pump Speed - Rotary Lobe Pump
Pump Speed n = Q x 100
q x ηv x 60
Where:
Q = Capacity (m3
/h)
/100 rev)
7.2.4
or
n = Q x 100
q x ηv
Where:
or
n = Q x 100
q x ηv
Where:
q = Pump Displacement (UK gal/100 rev)
331
14
Technical
Data

Where
to find
Flow Control - Centrifugal Pump
Connection between
Impeller Diameter and
Capacity
D2 = D1 x
Where:
D = Impeller Diameter (mm)
Q = Capacity (m3
/h)
7.3.2
Connection between
Head
D2 = D1 x
Where:
H = Head (m)
7.3.2
Connection between
Power
D2 = D1 x
Where:
P = Power (kW)
7.3.2
Reduction of Multi-
stage Impeller
Diameter D2 = D1 x
Where:
D1 = Standard Diameter (mm)
a = Maximum Working Point (m)
b = Minimum Working Point (m)
c = Required Working Point (m)
7.3.2
Connection between
Impeller Speed and
Capacity
n2 = n1 x
Where:
n = Impeller Speed (rev/min)
Q = Capacity (m3
/h)
7.3.2
Connection between
Impeller Speed and
Head
n2 = n1 x
Where:
H = Head (m)
7.3.2
Connection between
Impeller Speed and
Power
n2 = n1 x
Where:
P = Power (kW)
7.3.2
Table 14.2a
√
3 Q2
Q1
√H2
H1
√
3 P2
P1
Q2
Q1
√c-b
a-b
√
5 P2
P1
√H2
H1
332
14
Technical
Data

14.3 Conversion tables
14.3.1 Length
mm m cm in ft yd
1 0.001 0.10 0.0394 0.0033 0.0011
1000 1 100 39.370 3.2808 1.0936
10 0.01 1 0.3937 0.0328 0.1094
25.4 0.0254 2.540 1 0.0833 0.0278
304.8 0.3048 30.48 12 1 0.3333
914.4 0.9144 91.441 36 3 1
Table 14.3.1a
m3
cm3
l in3
ft3
UK gal US gal
1 100 x 104
1000 61024 35.315 220 264
10 x 107
1 10 x 10-4
0.0610 3.53 x 10-5
22 x 10-5
26.4 x 10-5
0.0010 1000 1 61.026 0.0353 0.22 0.2642
1.64 x 10-5
16.387 0.0164 1 58 x 10-5
0.0036 0.0043
0.00283 28317 28.317 1728 1 6.2288 7.4805
0.0045 4546.1 4.546 277.42 0.1605 1 1.201
37.88 x 10-4
3785.4 3.7853 231 0.1337 0.8327 1
Table 14.3.2a
14.3.2 Volume
m3
/h l/min hl/h UK gal/min US gal/min ft3
/h ft3
/s m3
/s
1 16.667 10 3.6667 4.3999 35.315 9.81 x 10-3
2.78 x 10-4
0.060 1 0.60 0.22 0.2642 2.1189 5.88 x 10-4
1.67 x 10-5
0.10 1.6667 1 0.3667 0.4399 3.5315 9.81 x 10-4
2.78 x 10-5
0.2727 4.546 2.7270 1 1.201 9.6326 2.67 x 10-3
7.57 x 10-5
0.2273 3.785 2.2732 0.8326 1 8.0208 2.23 x 10-3
6.31 x 10-5
0.0283 0.4719 0.2832 0.1038 0.1247 1 2.78 x 10-4
7.86 x 10-6
101.94 1699 1019.4 373.73 448.83 3600 1 0.0283
3600 6 x 104
36000 13200 15838 127208 35.315 1
Table 14.3.3a
14.3.3 Volumetric Capacity
333
14
Technical
Data

kg/s kg/h lb/h UK ton/h
t/d
(tonne/day)
t/h
(tonne/hour)
lb/s
1 3600 7936.6 3.5431 86.40 3.6 2.2046
2.78 x 10-4
1 2.2046 98.4 x 10-5
0.024 0.001 6.12 x 10-4
1.26 x 10-4
0.4536 1 44.6 x 10-5
0.0109 4.54 x 10-4
2.78 x 10-4
0.2822 1016.1 2240 1 24.385 1.0160 0.6222
11.57 x 10-3
41.667 91.859 0.0410 1 0.0417 0.0255
0.2778 1000 2201.8 0.9842 24 1 0.6116
0.4536 1632.9 3600 1.6071 39.190 1.6350 1
Table 14.3.4a
14.3.4 Mass Capacity
kN kgf lbf
1 101.97 224.81
9.81 x 10-3
1 2.2046
44.5 x 10-4
0.4536 1
Nm kgf m lb ft lb in
1 0.102 0.7376 8.8508
9.8067 1 7.2330 86.796
1.3558 0.1383 1 12
0.113 0.0115 0.0833 1
Table 14.3.6a
Table 14.3.7a
14.3.6 Force 14.3.7 Torque
bar kg/cm2
lb/in2
(PSI) ATM (water) ft (water) m mm Hg in Hg kPa
1 1.0197 14.504 0.9869 33.455 10.197 750.06 29.530 100
0.9807 1 14.223 0.9878 32.808 10 735.56 28.959 98.07
0.0689 0.0703 1 0.0609 2.3067 0.7031 51.715 2.036 6.89
1.0133 1.0332 14.696 1 33.889 10.332 760 29.921 101.3
0.0299 0.0305 0.4335 0.0295 1 0.3048 22.420 0.8827 2.99
0.0981 0.10 1.422 0.0968 3.2808 1 73.356 2.896 9.81
13.3 x 10-4
0.0014 0.0193 13.2 x 10-4
0.0446 0.0136 1 0.0394 0.133
0.0339 0.0345 0.4912 0.0334 1.1329 0.3453 25.40 1 3.39
1.0 x 10-5
10.2 x 10-6
14.5 x 10-5
9.87 x 10-6
3.34 x 10-4
10.2 x 10-5
75.0 x 10-4
29.5 x 10-5
1
Table 14.3.5a
14.3.5 Pressure/Head
14
Technical
Data

W kgf m/s ft lbf/s hp kW
1 0.102 0.7376 1.34 x 10-3
1000
9.8067 1 7.2330 0.0132 9806.7
1.3558 0.1383 1 1.82 x 10-3
1355.8
745.70 76.040 550 1 74.6 x 10-4
0.001 10.2 x 10-5
73.8 x 10-5
13.4 x 10-7
1
Table 14.3.4a
14.3.8 Power
kg/m3
g/cm3
lb/in3
lb/ft3
1 10-3
36.127 x 10-6
62.428 x 10-3
103
1 36.127 x 10-3
62.428
27.680 x 103
27.680 1 1.728 x 103
16.019 16.019 x 10-3
0.578 70 x 10-3
1
Table 14.3.9a
14.3.9 Density
335
14
Technical
Data

When SG = 1.0 When SG is
other than 1.0
Read Directly
Across
cP Poise cSt Stoke
Saybolt
Universal SSU
Seconds
Engler
Redwood
Standard #1
Ford
#3
Ford
#4
Zahn
#1
Zahn
#2
Zahn
#3
Zahn
#4
Zahn
#5
1 0.01 1 0.01 31 54 29
2 0.02 2 0.02 34 57 32
4 0.04 4 0.04 38 61 36
7 0.07 7 0.07 47 75 44 8
10 0.10 10 0.10 60 94 52 9 5 30 16
15 0.15 15 0.15 80 125 63 10 8 34 17
20 0.20 20 0.20 100 170 86 12 10 37 18
25 0.25 25 0.25 130 190 112 15 12 41 19
30 0.30 30 0.30 160 210 138 19 14 44 20
40 0.40 40 0.40 210 300 181 25 18 52 22
50 0.50 50 0.50 260 350 225 29 22 60 24
60 0.60 60 0.60 320 450 270 33 25 68 27
70 0.70 70 0.70 370 525 314 36 28 72 30
80 0.80 80 0.80 430 600 364 41 31 81 34
90 0.90 90 0.90 480 875 405 45 32 88 37 10
100 1.0 100 1.0 530 750 445 50 34 41 12 10
120 1.2 120 1.2 580 900 492 58 41 49 14 11
140 1.4 140 1.4 690 1050 585 66 45 58 16 13
160 1.6 160 1.6 790 1200 670 72 50 66 18 14
180 1.8 180 1.8 900 1350 762 81 54 74 20 16
200 2.0 200 2.0 1000 1500 817 90 58 82 23 17 10
220 2.2 220 2.2 1100 1650 933 98 62 88 25 18 11
240 2.4 240 2.4 1200 1800 1020 106 65 27 20 12
260 2.6 260 2.6 1280 1950 1085 115 68 30 21 13
280 2.8 280 2.8 1380 2100 1170 122 70 32 22 14
300 3.0 300 3.0 1475 2250 1250 130 74 34 24 15
320 3.2 320 3.2 1530 2400 1295 136 89 36 25 16
340 3.4 340 3.4 1630 2550 1380 142 95 39 26 17
360 3.6 360 3.6 1730 2700 1465 150 100 41 27 18
380 3.8 380 3.8 1850 2850 1570 160 106 43 29 19
400 4.0 400 4.0 1950 3000 1650 170 112 46 30 20
420 4.2 420 4.2 2050 3150 1740 180 118 48 32 21
440 4.4 440 4.4 2160 3300 1830 188 124 50 33 22
460 4.6 460 4.6 2270 3450 1925 200 130 52 34 23
480 4.8 480 4.8 2380 3600 2020 210 137 54 36 24
500 5.0 500 5.0 2480 3750 2100 218 143 58 38 25
550 5.5 550 5.5 2660 4125 2255 230 153 64 40 27
600 6.0 600 6.0 2900 4500 2460 250 170 68 45 30
700 7.0 700 7.0 3380 5250 2860 295 194 76 51 35
800 8.0 800 8.0 3880 6000 3290 340 223 57 40
900 9.0 900 9.0 4300 8750 3640 365 247 63 45
1000 10 1000 10 4600 7500 3900 390 264 69 49
1100 11 1100 11 5200 8250 4410 445 299 77 55
14.3.10 Viscosity Conversion Table
336
14
Technical
Data

Table 14.3.10a
When SG = 1.0 When SG is
other than 1.0
Read Directly
Across
cP Poise cSt Stoke
Saybolt
Universal SSU
Seconds
Engler
Redwood
Standard #1
Ford
#3
Ford
#4
Zahn
#1
Zahn
#2
Zahn
#3
Zahn
#4
Zahn
#5
1200 12 1200 12 5620 9000 4680 480 323 59
1300 13 1300 13 6100 9750 5160 520 350 64
1400 14 1400 14 6480 10350 5490 550 372 70
1500 15 1500 15 7000 11100 5940 595 400 75
1600 16 1600 16 7500 11850 6350 635 430 80
1700 17 1700 17 8000 12600 6780 680 460 85
1800 18 1800 18 8500 13300 7200 720 490 91
1900 19 1900 19 9000 13900 7620 760 520 96
2000 20 2000 20 9400 14600 7950 800 540
2100 21 2100 21 9850 15300 8350 835 565
2200 22 2200 22 10300 16100 8730 875 592
2300 23 2300 23 10750 16800 9110 910 617
2400 24 2400 24 11200 17500 9500 950 645
2500 25 2500 25 11600 18250 9830 985 676
3000 30 3000 30 14500 21800 12300 1230 833
3500 35 3500 35 16500 25200 14000 1400 950
4000 40 4000 40 18500 28800 15650 1570 1060
4500 45 4500 45 21000 32400 17800 1175
5000 50 5000 50 23500 36000 19900 1350
5500 55 5500 55 26000 39600 1495
6000 60 6000 60 28000 43100 1605
6500 65 6500 65 30000 46000 1720
7000 70 7000 70 32500 49600 1870
7500 75 7500 75 35000 53200 2010
8000 80 8000 80 37000 56800 2120
8500 85 8500 85 39500 60300 2270
9000 90 9000 90 41080 63900 2350
9500 95 9500 95 43000 67400 2470
10000 100 10000 100 46500 71000 2670
15000 150 15000 150 69400 106000
20000 200 20000 200 92500 140000
30000 300 30000 300 138500 210000
40000 400 40000 400 185000 276000
50000 500 50000 500 231000 345000
60000 600 60000 600 277500 414000
70000 700 70000 700 323500 484000
80000 800 80000 800 370000 550000
90000 900 90000 900 415500 620000
100000 1000 100000 1000 462000 689000
125000 1250 125000 1250 578000 850000
150000 1500 150000 1500 694000
175000 1750 175000 1750 810000
200000 2000 200000 2000 925000
337
14
Technical
Data

Minus 459.4 - 0 0 - 49 50 - 100 100 - 490 500 - 1000
° C to ° F ° C to ° F ° C to ° F ° C to ° F ° C to ° F
-273 -459 -17.8 0 32 10.0 50 122.0 38 100 212 260 500 932
-268 -450 -17.2 1 33.8 10.6 51 123.8 43 110 230 266 510 950
-262 -440 -16.7 2 35.6 11.1 52 125.6 49 120 248 271 520 968
-257 -430 -16.1 3 37.4 11.7 53 127.4 54 130 266 277 530 986
-251 -420 -15.6 4 39.2 12.2 54 129.2 60 140 284 282 540 1004
-246 -410 -15.0 5 41.0 12.8 55 131.0 66 150 302 288 550 1022
-240 -400 -14.4 6 42.8 13.3 56 132.8 71 160 320 293 560 1040
-234 -390 -13.9 7 44.6 13.9 57 134.6 77 170 338 299 570 1058
-229 -380 -13.3 8 46.4 14.4 58 136.4 82 180 356 304 580 1076
-223 -370 -12.8 9 48.2 15.0 59 138.2 88 190 374 310 590 1094
-218 -360 -12.2 10 50.0 15.6 60 140.0 93 200 392 316 600 1112
-212 -350 -11.7 11 51.8 16.1 61 141.8 99 210 410 321 610 1130
-207 -340 -11.1 12 53.6 16.7 62 143.6 100 212 414 327 620 1148
-201 -330 -10.6 13 55.4 17.2 63 145.4 104 220 428 332 630 1166
-196 -320 -10.0 14 57.2 17.8 64 147.2 110 230 446 338 640 1184
-190 -310 -9.4 15 59.0 18.3 65 149.0 116 240 464 343 650 1202
-184 -300 -8.9 16 60.8 18.9 66 150.8 121 250 482 349 660 1220
-179 -290 -8.3 17 62.6 19.4 67 152.6 127 260 500 354 670 1238
-173 -280 -7.8 18 64.4 20.0 68 154.4 132 270 518 360 680 1256
-169 -273 -459.4 -7.2 19 66.2 20.6 69 156.2 138 280 536 366 690 1274
-168 -270 -454 -6.7 20 68.0 21.1 70 158.0 143 290 554 371 700 1292
-162 -260 -436 -6.1 21 69.8 21.7 71 159.8 149 300 572 377 710 1310
-157 -250 -418 -5.6 22 71.6 22.2 72 161.6 154 310 590 382 720 1328
-151 -240 -400 -5.0 23 73.4 22.8 73 163.4 160 320 608 388 730 1346
-146 -230 -382 -4.4 24 75.2 23.3 74 165.2 166 330 626 393 740 1364
-140 -220 -364 -3.9 25 77.0 23.9 75 167.0 171 340 644 399 750 1382
-134 -210 -346 -3.3 26 78.8 24.4 76 168.8 177 350 662 404 760 1400
-129 -200 -328 -2.8 27 80.6 25.0 77 170.6 182 360 680 410 770 1418
-123 -190 -310 -2.2 28 82.4 25.6 78 172.4 188 370 698 416 780 1436
-118 -180 -292 -1.7 29 84.2 26.1 79 174.2 193 380 716 421 790 1454
-112 -170 -274 -1.1 30 86.0 26,7 80 176.0 199 390 734 427 800 1472
-107 -160 -256 -0.6 31 87.8 27.2 81 177.8 204 400 752 432 810 1490
-101 -150 -238 0.0 32 89.6 27.8 82 179.6 210 410 770 438 820 1508
14.3.11 Temperature Conversion Table
338
14
Technical
Data

Minus 459.4 - 0 0 - 49 50 - 100 100 - 490 500 - 1000
° C to ° F ° C to ° F ° C to ° F ° C to ° F ° C to ° F
-96 -140 -220 0.6 33 91.4 28.3 83 181.4 216 420 788 443 830 1526
-90 -130 -202 1.1 34 93.2 28.9 84 183.2 221 430 806 449 840 1544
-84 -120 -184 1.7 35 95.0 29.4 85 185.0 227 440 824 454 850 1562
-79 -110 -166 2.2 36 96.8 30.0 86 186.8 232 450 842 460 860 1580
-73 -100 -148 2.8 37 98.6 30.6 87 188.6 238 460 860 466 870 1598
-68 -90 -130 3.3 38 100.4 31.1 88 190.4 243 470 878 471 880 1616
-62 -80 -112 3.9 39 102.2 31.7 89 192.2 249 480 896 477 890 1634
-57 -70 -94 4.4 40 104.0 32.2 90 194.0 254 490 914 482 900 1652
-51 -60 -76 5.0 41 105.8 32.8 91 195.8 488 910 1670
-46 -50 -58 5.6 42 107.6 33.3 92 197.6 493 920 1688
-40 -40 -40 6.1 43 109.4 33.9 93 199.4 499 930 1706
-34 -30 -22 6.7 44 111.2 34.4 94 201.2 504 940 1724
-29 -20 -4 7.2 45 113.0 35.0 95 203.0 510 950 1742
-23 -10 14 7.8 46 114.8 35.6 96 204.8 516 960 1760
-17.8 0 32 8.3 47 116.6 36.1 97 206.6 521 970 1778
8.9 48 118.4 36.7 98 208.4 527 980 1796
9.4 49 120.2 37.2 99 210.2 532 990 1814
37.8 100 212.0 538 1000 1832
Locate temperature in the middle column. If in° C read the° F equivalent in the right hand column. If in° F read° C equivalent in the left hand
column.
° C = (° F - 32 ) x 0.5556° F = (° C x 1.8 ) + 32
Table 14.3.11a
339
14
Technical
Data

Temperature (° C) Density (p) (kg/m3
) Vapour Pressure (Pvp) (kPa)
0 999.8 0.61
5 1000.0 0.87
10 999.7 1.23
15 999.1 1.71
20 998.2 2.33
25 997.1 3.40
30 995.7 4.25
35 994.1 5.62
40 992.2 7.38
45 990.2 9.60
50 988.0 12.3
55 985.7 15.7
60 983.2 19.9
65 980.6 25.1
70 977.8 31.2
75 974.9 38.6
80 971.8 47.5
85 968.6 57.9
90 965.3 70.1
95 961.9 84.7
100 958.4 101.3
Vapour pressure: 1 bar = 100 kPa = 105
N/m2
Table 14.4a
14.4 Water Vapour Pressure Table
14
Technical
Data

14.5 Pressure Drop Curve for 100 m ISO/DIN Tube
Fig. 14.5a Pressure Drop Curve
A
B C D
E
F G H I J
K
L
M
N
0.1 1 10 100 1000
1
10
100
Capacity (m3
/h)
1 bar ≈ 10 m (metre liquid column)
Pressure drop (m)
0.1
A: 25 mm
B: DN25
C: 38 mm
D: DN40
I: 76 mm
J: DN80
K: 101.6 mm
L: DN100
E: 51 mm
F: DN50
G: 63.5 mm
H: DN65
M: DN125
N: DN150
341
14
Technical
Data

14.6 Velocity
(m/s) in ISO and DIN Tubes at various Capacities
Fig. 14.6a Connection between velocity and capacity at different tube dimensions
0 20,000
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
40,000 60,000 80,000 100,000 120,000 140,000 160,000 180,000 200,000
l/h
1 m3
/h = 1000 l/h
A: 1
B: DN25
C: 1½
D: DN40
I: 3
J: DN80
K: 4
L: DN100
E: 2
F: DN50
G: 2½
H: DN65
M: DN125
N: DN150
A
B C
D
E
F
G
H
I J
K
L
M
N
342
14
Technical
Data

14.7 Equivalent Tube Length Table
14.7.1 ISO Tube Metric for Water at 2 m/s
Unique SSV Standard Equivalent tube length in metres per unit
Unique SSV 25 mm 38 mm 51 mm 63.5 mm 76 mm 101.6 mm
Shut-off 2 4 6 5 5 18
Shut-off 2 3 5 5 4 18
Change-over 2 4 7 5 4 22
Change-over 2 6 9 8 5 20
Change-over 3 7 11 10 8 33
Change-over 4 7 11 15 12 31
Unique SSV Reverse Acting
RA 3 7 11 10 8 33
RA 3 7 11 10 8 33
RA 4 7 11 15 12 31
Table 14.7.1a - continues next page
343
14
Technical
Data

Unique SSV Long Stroke 25 mm 38 mm 51 mm 63.5 mm 76 mm 101.6 mm
Shut-off 4 3 4 4 11
Shut-off 1 2 3 3 4
Change-over 1 2 2 3 4
Unique SSV Tangential
Shut-off 6 6 5 47
Shut-off 5 5 4 17
Change-over 7 5 5 22
344
14
Technical
Data

Unique SSV Two step 25 mm 38 mm 51 mm 63.5 mm 76 mm 101.6 mm
Shut-off 4 6 6 5 47
Shut-off 3 4 5 4 17
Unique SSV Aseptic
Shut-off 2 5 8 9 8 28
Shut-off 2 4 6 8 9 41
Change-over 3 6 10 16 10 63
Change-over 3 8 13 15 9 43
Change-over 5 9 16 18 11 62
Change-over 4 8 23 19 13 69
345
14
Technical
Data

Unique SSV Tank Outlet 25 mm 38 mm 51 mm 63.5 mm 76 mm 101.6 mm
4 5 4 17
6 6 4 17
11 10 8 33
11 14 12 31
Other valves
Non-return valve LKC-2
7 10 12 21 20 26
Butterfly valve LKB
1 1 1 1 2 2
Koltek MH
1 2 3 5 6 7
1 2 4 6 9 10
Mixproof valves
Unique*
14 14 27 25 26
14 14 27 25 26
5 4 6 5 4
6 5 7 7 5
*Pressure drop/equivalent tube length is for unbalanced upper plug and balanced lower plug.
For other combinations use the Anytime Unique configuration tool.
346
14
Technical
Data

Mixproof valves Equivalent tube length in metres per unit
SMP-BC 25 mm 38 mm 51 mm 63.5 mm 76 mm 101.6 mm
3 3 4 3 6
3 6 11 8 18
3 5 7 7 11
7 11 13 15 32
6 10 13 14 31
9 12 34 25 101
6 12 34 23 101
347
14
Technical
Data

SMP-BCA 25 mm 38 mm 51 mm 63.5 mm 76 mm 101.6 mm
2 3 4 3 6
5 10 18 29 84
3 9 16 29 81
6 18 30 41 104
5 12 20 27 75
5 14 41 41 152
6 14 34 38 146
Unique Mixproof Tank Outlet
5 7 6 17
12 21 15 35
19 18 14 43
Tubes and fittings
Bend 90° 0.3 1 1 1 1 2
Bend 45° 0.2 0.4 1 1 1 1
Tee (out through side port) 1 2 3 4 5 7
Tee (in through side port) 1 2 2 3 4 5
Table 14.7.1a
348
14
Technical
Data

14.7.2 ISO Tube Feet for Water at 6 ft/s
Unique SSV Standard Equivalent tube length in feet per unit
Unique SSV 1 1.5 2 2.5 3 4
Shut-off 7 13 20 16 16 59
Shut-off 7 10 16 16 13 59
Change-over 7 13 23 16 13 72
Change-over 7 20 30 26 16 66
Change-over 10 23 36 33 26 108
Change-over 13 23 36 49 39 102
RA 10 23 36 33 26 108
RA 10 23 36 33 26 108
RA 13 23 36 49 39 102
349
14
Technical
Data

Unique SSV Long Stroke 1 1.5 2 2.5 3 4
Shut-off 13 10 13 13 36
Shut-off 3 7 10 10 13
Shut-off 20 20 16 154
Shut-off 16 16 13 56
350
14
Technical
Data

Unique SSV Two step 1 1.5 2 2.5 3 4
Shut-off 13 20 20 16 154
Shut-off 10 13 16 13 56
Change-over 10 23 16 13 72
Change-over 20 30 30 16 66
Change-over 23 36 33 26 108
Change-over 23 36 49 39 102
Unique SSV Aseptic
Shut-off 7 16 26 30 26 92
Shut-off 7 13 20 26 30 135
Change-over 10 20 33 52 33 207
Change-over 10 26 43 49 30 141
Change-over 16 30 52 59 36 203
Change-over 13 26 75 62 43 226
351
14
Technical
Data

Unique SSV Tank Outlet 1 1.5 2 2.5 3 4
13 16 13 56
20 20 13 56
36 33 26 108
36 46 39 102
Other valves
23 33 39 69 66 85
Butterfly valve LKB
3 3 3 3 7 7
Koltek MH
3 7 10 16 20 23
3 7 13 20 30 33
Mixproof valves
Unique*
46 46 89 82 85
46 46 89 82 85
16 13 20 16 13
20 16 23 23 16
352
14
Technical
Data

Mixproof valves Equivalent tube length in feet per unit
SMP-BC 1 1.5 2 2.5 3 4
10 10 13 10 20
10 20 36 26 59
10 16 23 23 36
23 36 43 49 105
20 33 43 46 102
30 39 112 82 331
20 39 112 75 331
353
14
Technical
Data

Mixproof valves Equivalent tube length in feet per unit
SMP-BCA 1 1.5 2 2.5 3 4
7 10 13 10 20
16 33 59 95 276
10 30 52 95 266
20 59 98 135 341
16 39 66 89 246
16 46 135 135 499
20 46 112 125 479
16 23 20 56
39 69 49 115
62 59 46 141
Tubes and fittings
Bend 90° 1 3 3 3 3 7
Bend 45° 1 1 3 3 3 3
Tee (out through side port) 3 7 10 13 16 13
Tee (in through side port) 3 7 7 10 13 16
Table 14.7.2a
354
14
Technical
Data

14.7.3 DIN Tube Metric for Water at 2 m/s
Unique SSV DN25 DN40 DN50 DN65 DN80 DN100 DN125 DN150
Shut-off 3 5 6 9 9 16 35 60
Shut-off 3 4 5 6 8 16 25 70
Change-over 3 5 7 7 9 21 30 65
Change-over 3 7 9 12 10 19 45 75
Change-over 4 8 12 14 17 31 60 150
Change-over 5 8 11 20 25 29 40 75
RA 5 8 11 20 25 29
RA 5 8 11 20 25 29
RA 4 8 12 14 17 31
355
14
Technical
Data

Unique SSV Long Stroke DN25 DN40 DN50 DN65 DN80 DN100 DN125 DN150
Shut-off 5 3 5 8 10
Shut-off 1 2 3 5 5
Shut-off 6 8 9 44
Shut-off 5 6 8 16
356
14
Technical
Data

Unique SSV Two step DN25 DN40 DN50 DN65 DN80 DN100 DN125 DN150
Shut-off 5 6 8 9 44
Shut-off 4 5 6 8 16
Unique SSV Aseptic
Shut-off 3 6 9 12 16 26
Shut-off 2 4 6 11 18 38
Change-over 3 7 11 22 20 59
Change-over 3 10 14 20 18 40
Change-over 7 11 17 25 23 59
Change-over 6 10 25 26 26 65
357
14
Technical
Data

Unique SSV Tank Outlet DN25 DN40 DN50 DN65 DN80 DN100 DN125 DN150
5 6 8 16
6 8 9 16
12 14 17 31
11 20 25 29
Other valves
14 14 15 32 36 30
Butterfly valve LKB
2 1 1 2 2 2 2 1
Koltek MH
2 2 5 9 10 8
2 2 5 9 14 13
Mixproof valves
Unique*
14 14 27 25 26 40 85
14 14 27 25 26 40 85
5 4 6 5 4 8 16
6 5 7 7 5 10 20
358
14
Technical
Data

SMP-BC DN25 DN40 DN50 DN65 DN80 DN100 DN125 DN150
3 4 5 5 7 4 8
4 7 13 15 21 38 78
4 6 11 12 20 31 61
9 17 22 24 40
7 13 22 23 37
10 15 52 44 114
9 15 52 44 114
359
14
Technical
Data

SMP-BCA DN25 DN40 DN50 DN65 DN80 DN100 DN125 DN150
3 4 5 5 6
6 13 32 51 97
3 12 25 49 94
9 24 46 72 124
6 15 30 46 84
8 20 62 67 174
9 21 54 54 167
Unique Mixproof 3 Body
25 37 48 55 40 85
13 37 45 34 38 79
8 15 21 28 40 85
14
Technical
Data

Table 14.7.3a
5 10 13 15
13 29 31 33
20 24 28 41
Tubes and fittings
Bend 90° 0.3 1 1 1 1 2 3 4
Bend 45° 0.2 0.4 1 1 1 1 2 2
Tee (out through side port) 1 2 3 4 5 7 9 10
Tee (in through side port) 1 2 2 3 4 5 7 8
361
14
Technical
Data

14.8 Moody Diagram
Fig. 14.8a Moody diagram for fD (after Miller)
Friction Factor
Relative Roughness
Reynolds
Number
10
3
0.008
0.009
0.01
0.015
0.02
0.025
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.1
Laminar
Flow
Critical
Zone
Transition
Zone
Complete
Turbulence,
Rough
Pipes
3
4
5
6
7
8
3
4
5
6
7
8
3
4
5
6
7
8
3
4
5
6
7
8
3
4
5
6
7
8
10
4
10
5
2(10
3
)
2(10
4
)
2(10
5
)
10
6
2(10
6
)
10
7
10
3
2(10
7
)
Riveted
steel
Concrete
Wood
stave
Cast
iron
Galvanised
steel
Asphalted
cast
iron
Commercial
steel
or
wrought
iron
Drawn
tubing
K
(mm)
1
-
10
0.3
-
3
0.2
-
1
0.25
0.15
0.12
0.045
0.0015
A
=
0.05
B
=
0.04
C
=
0.03
D
=
0.02
E
=
0.015
F
=
0.01
G
=
0.008
H
=
0.006
I
=
0.004
J
=
0.002
K
=
0.001
L
=
0.0008
M
=
0.0006
N
=
0.0004
O
=
0.0002
P
=
0.0001
Q
=
0.00005
R
=
0.00001
S
=
0.000005
T
=
0.000001
U
=
Smooth
pipes
V
=
R
cr
X
=
Laminar
flow
f
=
64
R
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
X
362
14
Technical
Data

14.9 Initial Suction Line Sizing
Fig. 14.9a Initial suction line sizing
100
A = ½ - DN15
B = ¾ - DN20
C = 1 - DN25
D = 1½ - DN40
E = 2 - DN50
F = 2½ - DN65
G = 3 - DN80
H = 4 - DN100
I = 5 - DN125
J = 6 - DN150
K = 8 - DN200
0.1
1
10
100
1
1000
1,000 10,000 Viscosity - cSt
Flow
rate
-
m
3
/h
100,000
A
B
C
D
E
F
G
H
I
J
K
363
14
Technical
Data

14.10 Elastomer Compatibility Guide
Listed below are fluids commonly pumped.
The elastomer compatibility is for guidance purposes
only as this may be affected by temperature.
The fluid viscous behaviour type shown relates to
general terms - in some instances Pseudoplastic fluids
can have Thixotropic tendencies.
(†) - Fluid can become Dilatant at high concentration
and high shear rate.
(‡) - If low concentration, this can be Newtonian.
Name of Fluid Pumped Elastomer Material Viscous Behaviour Type
NBR EPDM FPM PTFE/
FFPM
ACETIC ACID   Newtonian
ACETONE   Newtonian
ADHESIVE - SOLVENT BASED  Pseudoplastic
ADHESIVE - WATER BASED   Pseudoplastic
ALUM SLUDGE     Pseudoplastic
AMMONIUM HYDROXIDE   Newtonian
ANIMAL FAT   Newtonian
BABY BATH   Pseudoplastic
BABY LOTION   Pseudoplastic
BABY OIL   Newtonian
BATH FOAM   Pseudoplastic
BATTER    Pseudoplastic
BEER    Newtonian
BENTONITE SUSPENSION     Pseudoplastic (†)
BISCUIT CREAM   Pseudoplastic
BISULPHITE     Newtonian
BITUMEN    Pseudoplastic
BLACK LIQUOR   Newtonian
BLEACH    Newtonian
BLOOD    Newtonian
BODY LOTION   Pseudoplastic
BODY SCRUB   Pseudoplastic
BRINE     Newtonian
BUTTER    Pseudoplastic
CALCIUM CARBONATE SLURRY     Pseudoplastic
CARAMEL - COLOURING    Newtonian
CARAMEL - TOFFEE    Pseudoplastic
CASTOR OIL    Newtonian
Table 14.10a Elastomer compatibility guide - continues next page
364
14
Technical
Data

NBR EPDM FPM PTFE/
FFPM
CELLULOSE ACETATE DOPE  Pseudoplastic
CELLULOSE SUSPENSION     Pseudoplastic
CERAMIC SLIP     Pseudoplastic (†)
CHEESE    Pseudoplastic
CHEWING GUM  Pseudoplastic
CHINA CLAY SLURRY     Pseudoplastic (†)
CHOCOLATE   Pseudoplastic
CHROMIC ACID   Newtonian
CHUTNEY    Pseudoplastic
CITRIC ACID     Newtonian
COAL TAR   Newtonian
COCOA BUTTER   Newtonian
COCOA LIQUOR   Pseudoplastic
COCONUT CREAM   Pseudoplastic
COLLAGEN GEL    Pseudoplastic
CONDENSED MILK    Pseudoplastic
COPPER SULPHATE    Newtonian
CORN STEEP LIQUOR    Newtonian
CORN SYRUP     Newtonian
COSMETIC CREAM   Pseudoplastic
COUGH SYRUP    Pseudoplastic
CRUDE OIL   Pseudoplastic
CUSTARD    Pseudoplastic
DAIRY CREAM    Pseudoplastic
DETERGENT - AMPHOTERIC   Newtonian
DETERGENT - ANIONIC     Pseudoplastic (‡)
DETERGENT - CATIONIC   Newtonian
DETERGENT - NONIONIC    Newtonian
DIESEL OIL    Newtonian
DODECYL BENZENE SULPHONIC ACID   Newtonian
DRILLING MUD     Pseudoplastic
DYE    Newtonian
EGG    Pseudoplastic
ENZYME SOLUTION   Newtonian
ETHANOL    Newtonian
ETHYLENE GLYCOL     Newtonian
FABRIC CONDITIONER   Pseudoplastic
FATS   Newtonian
FATTY ACID   Newtonian
FERRIC CHLORIDE     Newtonian
FERTILISER     Pseudoplastic
FILTER AID     Pseudoplastic
365
14
Technical
Data

NBR EPDM FPM PTFE/
FFPM
FININGS    Pseudoplastic
FIRE FIGHTING FOAM   Pseudoplastic
FISH OIL   Newtonian
FONDANT    Pseudoplastic
FORMIC ACID   Newtonian
FROMAGE FRAIS    Pseudoplastic
FRUCTOSE    Newtonian
FRUIT JUICE CONCENTRATE    Pseudoplastic
FRUIT PUREE    Pseudoplastic
FUDGE    Pseudoplastic
GELATINE    Pseudoplastic
GLUCOSE    Newtonian
GLYCERINE     Newtonian
GREASE    Pseudoplastic
GYPSUM SLURRY     Pseudoplastic
HAIR CONDITIONER   Pseudoplastic
HAIR GEL   Pseudoplastic
HAND CLEANSER   Pseudoplastic
HONEY    Pseudoplastic
HYDROCHLORIC ACID   Newtonian
HYDROGEN PEROXIDE   Newtonian
ICE CREAM MIX    Pseudoplastic
INK - PRINTING   Pseudoplastic
INK - WATER BASED    Newtonian
ISOBUTYL ALCOHOL    Newtonian
ISOCYANATE  Newtonian
ISOPROPANOL    Newtonian
JAM    Pseudoplastic
KEROSENE    Newtonian
LACTIC ACID   Newtonian
LACTOSE    Newtonian
LANOLIN   Newtonian
LATEX   Pseudoplastic
LECITHIN   Newtonian
LIPSTICK   Pseudoplastic
LIQUORICE   Pseudoplastic
MAGMA    Pseudoplastic
MAIZE STARCH SLURRY     Pseudoplastic
MALT EXTRACT    Pseudoplastic
MANGANESE NITRATE   Newtonian
MASCARA   Pseudoplastic
MASHED POTATO    Pseudoplastic
366
14
Technical
Data

NBR EPDM FPM PTFE/
FFPM
MASSECUITE    Pseudoplastic
MAYONNAISE  Pseudoplastic
MEAT PASTE    Pseudoplastic
METHANOL    Newtonian
METHYL ETHYL KETONE SOLVENT   Newtonian
METHYLATED SPIRIT    Newtonian
METHYLENE CHLORIDE   Newtonian
MILK    Newtonian
MINCEMEAT    Pseudoplastic
MINERAL OIL    Newtonian
MOLASSES    Newtonian
MUSTARD    Pseudoplastic
NEAT SOAP   Pseudoplastic
NITRIC ACID   Newtonian
PAINTS - SOLVENT BASED  Pseudoplastic
PAINTS - WATER BASED     Pseudoplastic
PAPER COATING - CLAY   Pseudoplastic (†)
PAPER COATING - PIGMENT     Pseudoplastic (†)
PAPER COATING - STARCH     Pseudoplastic
PAPER PULP     Pseudoplastic
PEANUT BUTTER   Pseudoplastic
PERACETIC ACID  Newtonian
PETFOOD    Pseudoplastic
PETROLEUM    Newtonian
PHOSPHORIC ACID   Newtonian
PHOTOGRAPHIC EMULSION    Pseudoplastic
PLASTISOL   Newtonian
POLYETHYLENE GLYCOL    Newtonian
POLYVINYL ALCOHOL    Pseudoplastic
POTASSIUM HYDROXIDE   Newtonian
PROPIONIC ACID  Newtonian
PROPYLENE GLYCOL     Newtonian
QUARG    Pseudoplastic
RESIN   Newtonian
RUBBER SOLUTION  Pseudoplastic
SAUCE - CONFECTIONERY   Pseudoplastic
SAUCE - VEGETABLE    Pseudoplastic
SAUSAGE MEAT    Pseudoplastic
SEWAGE SLUDGE     Pseudoplastic
SHAMPOO   Pseudoplastic
SHAVING CREAM   Pseudoplastic
SILICONE OIL     Newtonian
367
14
Technical
Data

NBR EPDM FPM PTFE/
FFPM
SODIUM HYDROXIDE   Newtonian
SODIUM SILICATE    Newtonian
SORBIC ACID  Newtonian
SORBITOL     Newtonian
STARCH    Pseudoplastic
SUGAR PULP - BEET    Pseudoplastic
SUGAR PULP - CANE    Pseudoplastic
SUGAR SYRUP    Newtonian
SULPHURIC ACID   Newtonian
TALL OIL   Newtonian
TALLOW   Newtonian
TITANIUM DIOXIDE     Pseudoplastic (†)
TOBACCO FLAVOURING  Newtonian
TOLUENE   Newtonian
TOMATO KETCHUP    Pseudoplastic
TOMATO PUREE    Pseudoplastic
TOOTHPASTE   Pseudoplastic
TRUB     Pseudoplastic
UREA    Newtonian
VARNISH  Newtonian
VASELINE    Pseudoplastic
VEGETABLE GUM    Pseudoplastic
VEGETABLE OIL   Newtonian
VITAMIN SOLUTION    Newtonian
WATER     Newtonian
WAX   Newtonian
WHEY    Newtonian
WHITE SPIRIT   Newtonian
WINE    Newtonian
WORT    Newtonian
XYLENE   Newtonian
YEAST    Pseudoplastic
YOGHURT    Pseudoplastic
ZEOLITE SLURRY     Pseudoplastic (†)
ZIRCONIA SLURRY     Pseudoplastic (†)
Table 14.10a Elastomer compatibility guide
368
14
Technical
Data

369
14
Technical
Data

This chapter explains the various
terms found in this handbook.
370
15
Glossary
of
Terms

Glossary of Terms
15
371
15
Glossary
of
Terms

A
Absolute Pressure Total pressure exerted by a fluid i.e., atmospheric pressure plus gauge pressure
Absolute Viscosity Measure of how resistive the flow of a fluid is between two layers of fluid in motion
Adaptor Connection piece between the motor and back plate on a centrifugal and liquid ring pump
Anti-thixotropic Fluid viscosity increases with time under shear conditions
Air-screw A screw type Impeller fitted in the offset priming chamber to assist in evacuating air or gas
B
Back Plate
Part of a centrifugal and liquid ring pump, which together with the pump casing forms the
fluid chamber
C
Cartridge seal NO EXPLANATION in Word
Cavitation Vacuous space in the inlet port of a pump normally occupied by fluid
CPP
Circumferential Piston Pump (CPP) has a pair of rotating winged rotors (pistons) moving liquid
around the circumference of the casing channel
Centrifugal Tending to move out from the center
Chamber
For Twin Screw pumps: The chamber is the free distance between the rear of the helix and the
front of the next helix in which product is moved, to this extent the chamber size determines
the maximum particle size for solids handling
CIP Cleaning In Place - ability to clean pump system without dismantling pump and system
Clearflow
Special Impeller design on LKH Evap pumps to prevent crystalline build up on pump
backplate
CM Condition Monitor – measures vibrations and temperature
CM Connect
Gateway for sending data from up to 10 CM, condition monitors, to the GSM, Gateway for
sending data to the Cloud, from network on CM’s
D
Dead Head Speed Pump speed required to overcome slip for a rotary lobe pump
Density Fluids mass per unit of volume
Differential Pressure
Total absolute pressure differences across the pump during operation i.e., discharge pressure
minus suction pressure
Diffusion Hardening
A process used in manufacturing that increases the hardness of steels. Diffusion only hap-
pens through a small thickness of a piece of steel, so only the surface is hardened while the
core maintains its original mechanical properties
Dilatant Fluid viscosity increases as shear rate increases
Discharge Pressure Pressure at which fluid is leaving the pump
Duty Point Intersection point between the pump curve and the process curve
Dynamic Head Energy required to set fluid in motion and to overcome any resistance to that motion
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E
Elastomer Non-metallic sealing device that exhibits elastic strain characteristics
Electropolishing Method of surface finishing achieved by an electro-chemical process
F
Feed Screw Helical Screw rotor for the Twin Screw pump
Flooded Suction Positive inlet pressure/head
Friction Head
Pressure drop on both inlet and discharge sides of the pump due to frictional losses in fluid
flow
G
Gauge Pressure
Pressure within a gauge that exceeds the surrounding atmospheric pressure, using atmos-
pheric pressure as a zero reference
H
Hydraulic Power Theoretical energy required to pump a given quantity of fluid against a given total head
I
Impeller Pumping element of a centrifugal and liquid ring pump
Inlet Pressure Pressure at which fluid is entering the pump
K
Kinematic Viscosity Measure of how resistive the flow of a fluid is under the influence of gravity
L
Laminar Flow
Flow characteristic whereby the fluid moves through the pipe in concentric layers with its max-
imum velocity in the center of the pipe, decreasing to zero at the pipe wall
M
Multi-stage
A pump with more than one impeller mounted on the same shaft and connected so as to act
in series
N
Newtonian Fluid viscosity is constant with change in shear rate or agitation
NPSH Net Positive Suction Head describing the inlet condition of a pump and system
NPSHa Net Positive Suction Head available in a system
NPSHr Net Positive Suction Head required from a pump
NIPA Net Inlet Pressure Available in a system
NIPR Net Inlet Pressure Required from a pump
Non-Product Wetted Metallic and elastomeric components not in contact with the fluid being pumped
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Terms

O
Outlet Pressure Pressure at which fluid is leaving the pump
P
Pitch
The pitch length which is basically the dimension from the rear face of the of the helix to the
front of the next helix
Positive Displacement Pump type whereby the fluid pumped is directly displaced
Pressure Drop Result of frictional losses in pipework, fittings, and other process equipment
Pressure Shock Result of change in fluid velocity
Product Wetted Metallic and elastomeric components in contact with the fluid being pumped
Profiled Seal Ring Seal ring with optimized hygienic design minimizing crevasses for easy CIP cleaning
Pseudoplastic Fluid viscosity decreases as shear rate increases
Pump Casing
Part of a centrifugal and liquid ring pump, which together with the back plate forms the fluid
chamber
R
Required Power Power needed at the pump shaft
Reynolds Number (Re) Ratio of inertia forces to viscous forces giving a value to determine type of flow characteristic
Rheology Science of fluid flow
Rheomalactic Fluid viscosity decreases with time under shear conditions but does not recover
Rotodynamic
A machine to transfer rotating mechanical energy into kinetic energy in the form of fluid veloc-
ity and pressure
Rotor Pumping element of a rotary lobe pump
Rotor Case Part of a rotary lobe pump, which together with the rotor case cover forms the pump chamber
Rotor Case Cover Part of a rotary lobe pump, which together with the rotor case forms the pump chamber
Rumbling Method of surface finishing achieved by vibrating components with abrasive particulate
S
Shotblasting
Method of surface finishing achieved by blasting finished components with small metallic
particles at great force
SIP
Steam or Sterilisation In Place - ability to steam clean or sterilise pump system without dis-
mantling pump and system
Slip Fluid lost by leakage through the pump clearances of a rotary lobe pump
Specific Gravity Ratio of a fluid’s density to the density of water
Specific Weight Fluid’s weight per unit volume
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S
Static Head Difference in fluid levels
Static Discharge Head
Difference in height between the fluid level and the centre line of the pump inlet on the dis-
charge side of the pump
Static Suction Head
Difference in height between the fluid level and the centre line of the pump inlet on the inlet
side of the pump
Suction Lift Fluid level is below the centre line of the pump inlet
Suction Pressure Pressure at which fluid is entering the pump
T
Thermal Shock Rapid temperature change of pump head components
Thixotropic Fluid viscosity decreases with time under shear conditions
Timing Gear Setting the timing between the Rotors or the Feed Screws in the gearbox
TLA
Timing gear location via Torque Locking Assembly (TLA) providing full 360° uniform loading
and easy time setting
Torque Moment of force required to produce rotation
Total Discharge Head Sum of the static discharge and dynamic heads
Total Efficiency
Relationship between the input power at the pump shaft and output power in the form of
water horsepower
Total Head
Total pressure difference between the total discharge head and the total suction head of the
pump
Total Static Head Difference in height between the static discharge head and the static suction head
Total Suction Head Static suction head less the dynamic head
Transitional Flow Flow characteristic combining both laminar and turbulent flow tendencies
TS Pump Twin Screw Pump
Turbulent Flow
Flow characteristic whereby considerable mixing of the fluid takes place across a pipe section
with velocity remaining fairly constant
V
Vacuum Pressure in a pumping system below normal atmospheric pressure
Vapour Pressure Pressure at which a fluid will change to a vapour, at a given temperature
Velocity Distance a fluid moves per unit of time
Viscosity Measure of how resistive a fluid is to flow
Viscous Power Power loss due to viscous fluid friction within the pump
Volumetric Efficiency Ratio of actual capacity against theoretical capacity
375
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Glossary
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Terms

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Information and services provided in this document are made as a benefit and service to the user, and
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services for any purpose.
100017121-2-EN 2310
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Alfa Laval Pump Handbook - Second Edition 2023

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Alfa Laval Pump Handbook - Second Edition 2023